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102-412: DECtalk was a speech synthesizer and text-to-speech technology developed by Digital Equipment Corporation in 1983, based largely on the work of Dennis Klatt at MIT , whose source-filter algorithm was variously known as KlattTalk or MITalk. Uses ranged from interacting with the public to allowing those with speech disabilities to verbalize, include giving a public speech. Announced December 1983,
204-404: A desperate and cheap substitute for regular ethanol alcoholic beverages . It is important that people be examined by someone specializing in low vision care prior to other rehabilitation training to rule out potential medical or surgical correction for the problem and to establish a careful baseline refraction and prescription of both normal and low vision glasses and optical aids. Only a doctor
306-429: A 1.5-fold risk of reporting perceived discrimination and of these individuals, there was a 2-fold risk of loneliness and 4-fold risk of reporting a lower quality of life. Among adults with visual impairment, the prevalence of moderate loneliness is 28.7% (18.2% in general population) and prevalence of severe loneliness is 19.7% (2.7% in general population). The risk of depression and anxiety are also increased in
408-462: A 1791 paper. This machine added models of the tongue and lips, enabling it to produce consonants as well as vowels. In 1837, Charles Wheatstone produced a "speaking machine" based on von Kempelen's design, and in 1846, Joseph Faber exhibited the " Euphonia ". In 1923, Paget resurrected Wheatstone's design. In the 1930s, Bell Labs developed the vocoder , which automatically analyzed speech into its fundamental tones and resonances. From his work on
510-434: A State plan approved under title X or XVI as in effect for October 1972 and received aid under such plan (on the basis of blindness) for December 1973, so long as he is continuously blind as so defined. Vision impairment for a few seconds, or minutes, may occur due to any of a variety of causes, some serious and requiring medical attention. Visual impairments may take many forms and be of varying degrees. Visual acuity alone
612-437: A condition in which a person's circadian rhythm , normally slightly longer than 24 hours, is not entrained (synchronized) to the light–dark cycle. The most common causes of visual impairment globally in 2010 were: The most common causes of blindness worldwide in 2010 were: About 90% of people who are visually impaired live in the developing world . Age-related macular degeneration, glaucoma, and diabetic retinopathy are
714-418: A correcting lens. An eye which is accompanied by a limitation in the fields of vision such that the widest diameter of the visual field subtends an angle no greater than 20 degrees shall be considered for purposes of the first sentence of this subsection as having a central visual acuity of 20/200 or less. An individual shall also be considered to be blind for purposes of this title if he is blind as defined under
816-482: A database of speech samples. They can therefore be used in embedded systems , where memory and microprocessor power are especially limited. Because formant-based systems have complete control of all aspects of the output speech, a wide variety of prosodies and intonations can be output, conveying not just questions and statements, but a variety of emotions and tones of voice. Examples of non-real-time but highly accurate intonation control in formant synthesis include
918-415: A female voice. Kurzweil predicted in 2005 that as the cost-performance ratio caused speech synthesizers to become cheaper and more accessible, more people would benefit from the use of text-to-speech programs. The most important qualities of a speech synthesis system are naturalness and intelligibility . Naturalness describes how closely the output sounds like human speech, while intelligibility
1020-710: A heterogonous mechanism associated with structural change and chronic inflammation. In addition, often pediatric glaucoma differs greatly in cause and management from the glaucoma developed by adults. Currently, the best sign of pediatric glaucoma is an IOP of 21 mm Hg or greater present within a child. One of the most common causes of pediatric glaucoma is cataract removal surgery, which leads to an incidence rate of about 12.2% among infants and 58.7% among 10-year-olds. Childhood blindness can be caused by conditions related to pregnancy, such as congenital rubella syndrome and retinopathy of prematurity . Leprosy and onchocerciasis each blind approximately 1 million individuals in
1122-543: A home computer. Many computer operating systems have included speech synthesizers since the early 1990s. A text-to-speech system (or "engine") is composed of two parts: a front-end and a back-end . The front-end has two major tasks. First, it converts raw text containing symbols like numbers and abbreviations into the equivalent of written-out words. This process is often called text normalization , pre-processing , or tokenization . The front-end then assigns phonetic transcriptions to each word, and divides and marks
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#17327803893531224-529: A lack of universally agreed objective evaluation criteria. Different organizations often use different speech data. The quality of speech synthesis systems also depends on the quality of the production technique (which may involve analogue or digital recording) and on the facilities used to replay the speech. Evaluating speech synthesis systems has therefore often been compromised by differences between production techniques and replay facilities. Visual impairment Visual or vision impairment ( VI or VIP )
1326-405: A low vision specialist (optometrist or ophthalmologist) is to maximize the functional level of a patient's vision by optical or non-optical means. Primarily, this is by use of magnification in the form of telescopic systems for distance vision and optical or electronic magnification for near tasks. People with significantly reduced acuity may benefit from training conducted by individuals trained in
1428-488: A number based on surrounding words, numbers, and punctuation, and sometimes the system provides a way to specify the context if it is ambiguous. Roman numerals can also be read differently depending on context. For example, "Henry VIII" reads as "Henry the Eighth", while "Chapter VIII" reads as "Chapter Eight". Similarly, abbreviations can be ambiguous. For example, the abbreviation "in" for "inches" must be differentiated from
1530-537: A number of built-in voices which were identified by the following names: Perfect Paul (the default voice), Beautiful Betty, Huge Harry, Frail Frank, Kit the Kid, Rough Rita, Uppity Ursula, Doctor Dennis and Whispering Wendy. Each of the voices were editable by adjusting various parameters (such as throat size, crossover frequencies, etc.). DECtalk understood phonetic spellings of words, allowing customized pronunciation of unusual words. These phonetic spellings could also include
1632-420: A person can do any work for which eyesight is essential, not just one particular job (such as their job before becoming blind). In practice, the definition depends on individuals' visual acuity and the extent to which their field of vision is restricted. The Department of Health identifies three groups of people who may be classified as severely visually impaired. The Department of Health also state that
1734-465: A person is more likely to be classified as severely visually impaired if their eyesight has failed recently or if they are an older individual, both groups being perceived as less able to adapt to their vision loss. In the United States, any person with vision that cannot be corrected to better than 20/200 in the better eye, or who has 20 degrees ( diameter ) or less of visual field remaining,
1836-567: A pitch and duration notation which DECtalk would use when enunciating the phonetic components. This allowed DECtalk to sing. Speech synthesizer Speech synthesis is the artificial production of human speech . A computer system used for this purpose is called a speech synthesizer , and can be implemented in software or hardware products. A text-to-speech ( TTS ) system converts normal language text into speech; other systems render symbolic linguistic representations like phonetic transcriptions into speech. The reverse process
1938-441: A quarter mile (400 m) and walking up stairs, as compared to those with normal vision. Older adults with vision loss are at an increased risk of memory loss, cognitive impairment, and cognitive decline. Studies demonstrate an association between older adults with visual impairment and a poor mental health; discrimination was identified as one of the causes of this association. Older adults with visual impairment have
2040-467: A result, corneal scarring from all causes is now the fourth greatest cause of global blindness. Eye injuries , most often occurring in people under 30, are the leading cause of monocular blindness (vision loss in one eye) throughout the United States . Injuries and cataracts affect the eye itself, while abnormalities such as optic nerve hypoplasia affect the nerve bundle that sends signals from
2142-617: A specialized software that enabled it to read Italian. A second version, released in 1978, was also able to sing Italian in an " a cappella " style. Dominant systems in the 1980s and 1990s were the DECtalk system, based largely on the work of Dennis Klatt at MIT, and the Bell Labs system; the latter was one of the first multilingual language-independent systems, making extensive use of natural language processing methods. Handheld electronics featuring speech synthesis began emerging in
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#17327803893532244-411: A synthesizer can incorporate a model of the vocal tract and other human voice characteristics to create a completely "synthetic" voice output. The quality of a speech synthesizer is judged by its similarity to the human voice and by its ability to be understood clearly. An intelligible text-to-speech program allows people with visual impairments or reading disabilities to listen to written words on
2346-468: A tool developed by ElevenLabs to create voice deepfakes that defeated a bank's voice-authentication system. The process of normalizing text is rarely straightforward. Texts are full of heteronyms , numbers , and abbreviations that all require expansion into a phonetic representation. There are many spellings in English which are pronounced differently based on context. For example, "My latest project
2448-481: A trickle came February 1984; larger DECtalk quantities were delivered in March. They were standalone units that connected to any device with an asynchronous serial port . These units were also able to connect to the telephone system by having two telephone jacks. One connected to a phone line, the other to a telephone. The DECtalk units could recognize and generate any telephone touch tone . With that capability
2550-438: A waveguide or transmission-line analog of the human oral and nasal tracts controlled by Carré's "distinctive region model". More recent synthesizers, developed by Jorge C. Lucero and colleagues, incorporate models of vocal fold biomechanics, glottal aerodynamics and acoustic wave propagation in the bronchi, trachea, nasal and oral cavities, and thus constitute full systems of physics-based speech simulation. HMM-based synthesis
2652-411: Is speech recognition . Synthesized speech can be created by concatenating pieces of recorded speech that are stored in a database . Systems differ in the size of the stored speech units; a system that stores phones or diphones provides the largest output range, but may lack clarity. For specific usage domains, the storage of entire words or sentences allows for high-quality output. Alternatively,
2754-442: Is a synthesis method based on hidden Markov models , also called Statistical Parametric Synthesis. In this system, the frequency spectrum ( vocal tract ), fundamental frequency (voice source), and duration ( prosody ) of speech are modeled simultaneously by HMMs. Speech waveforms are generated from HMMs themselves based on the maximum likelihood criterion. Sinewave synthesis is a technique for synthesizing speech by replacing
2856-583: Is a useful predictor of overall well-being, and routine physical activity reduces the risk of developing chronic diseases and disability. Older adults with visual impairment (including glaucoma, age-related macular degeneration, and diabetic retinopathy) have decreased physical activity as measured with self-reports and accelerometers. The US National Health and Nutrition Examination Survey (NHANES) showed that people with corrected visual acuity of less than 20/40 spent significantly less time in moderate to vigorous physical activity. Age-related macular degeneration
2958-430: Is also associated with a 50% decrease in physical activity–however physical activity is protective against age-related macular degeneration progression. In terms of mobility, those with visual impairment have a slower gait speed than those without visual impairment; however, the rate of decline remains proportional with increasing age in both groups. Additionally, the visually impaired also have greater difficulty walking
3060-521: Is an eye disease often characterized by increased pressure within the eye or intraocular pressure (IOP). Glaucoma causes visual field loss as well as severs the optic nerve. Early diagnosis and treatment of glaucoma in patients is imperative because glaucoma is triggered by non-specific levels of IOP. Also, another challenge in accurately diagnosing glaucoma is that the disease has four causes: 1) inflammatory ocular hypertension syndrome (IOHS); 2) severe uveitic angle closure; 3) corticosteroid-induced; and 4)
3162-406: Is an important technology for speech synthesis and coding, and in the 1990s was adopted by almost all international speech coding standards as an essential component, contributing to the enhancement of digital speech communication over mobile channels and the internet. In 1975, MUSA was released, and was one of the first Speech Synthesis systems. It consisted of a stand-alone computer hardware and
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3264-466: Is another problem that TTS systems have to address. It is a simple programming challenge to convert a number into words (at least in English), like "1325" becoming "one thousand three hundred twenty-five". However, numbers occur in many different contexts; "1325" may also be read as "one three two five", "thirteen twenty-five" or "thirteen hundred and twenty five". A TTS system can often infer how to expand
3366-531: Is built to adjust the intonation and pacing of delivery based on the context of language input used. It uses advanced algorithms to analyze the contextual aspects of text, aiming to detect emotions like anger, sadness, happiness, or alarm, which enables the system to understand the user's sentiment, resulting in a more realistic and human-like inflection. Other features include multilingual speech generation and long-form content creation with contextually-aware voices. The DNN-based speech synthesizers are approaching
3468-412: Is characterized by decreased peripheral vision and trouble seeing at night. Advances in mapping of the human genome have identified other genetic causes of low vision or blindness. One such example is Bardet–Biedl syndrome . Rarely, blindness is caused by the intake of certain chemicals. A well-known example is methanol , which is only mildly toxic and minimally intoxicating, and breaks down into
3570-495: Is considered legally blind or eligible for disability classification and possible inclusion in certain government sponsored programs. The terms partially sighted , low vision , legally blind and totally blind are used by schools, colleges, and other educational institutions to describe students with visual impairments. They are defined as follows: In 1934, the American Medical Association adopted
3672-423: Is contained in the speech database. At runtime, the target prosody of a sentence is superimposed on these minimal units by means of digital signal processing techniques such as linear predictive coding , PSOLA or MBROLA . or more recent techniques such as pitch modification in the source domain using discrete cosine transform . Diphone synthesis suffers from the sonic glitches of concatenative synthesis and
3774-663: Is not always a good predictor of an individual's function. Someone with relatively good acuity (e.g., 20/40) can have difficulty with daily functioning, while someone with worse acuity (e.g., 20/200) may function reasonably well if they have low visual demands. Best-corrected visual acuity differs from presenting visual acuity; a person with a "normal" best corrected acuity can have "poor" presenting acuity (e.g. individual who has uncorrected refractive error). Thus, measuring an individual's general functioning depends on one's situational and contextual factors, as well as access to treatment. The American Medical Association has estimated that
3876-504: Is not always the goal of a speech synthesis system, and formant synthesis systems have advantages over concatenative systems. Formant-synthesized speech can be reliably intelligible, even at very high speeds, avoiding the acoustic glitches that commonly plague concatenative systems. High-speed synthesized speech is used by the visually impaired to quickly navigate computers using a screen reader . Formant synthesizers are usually smaller programs than concatenative systems because they do not have
3978-684: Is of uncertain benefit. Diagnosis is by an eye exam . The World Health Organization (WHO) estimates that 80% of visual impairment is either preventable or curable with treatment. This includes cataracts, the infections river blindness and trachoma , glaucoma, diabetic retinopathy, uncorrected refractive errors, and some cases of childhood blindness. Many people with significant visual impairment benefit from vision rehabilitation , changes in their environment, and assistive devices. As of 2015 , there were 940 million people with some degree of vision loss. 246 million had low vision and 39 million were blind. The majority of people with poor vision are in
4080-406: Is quick and accurate, but completely fails if it is given a word which is not in its dictionary. As dictionary size grows, so too does the memory space requirements of the synthesis system. On the other hand, the rule-based approach works on any input, but the complexity of the rules grows substantially as the system takes into account irregular spellings or pronunciations. (Consider that the word "of"
4182-415: Is quite successful for many cases such as whether "read" should be pronounced as "red" implying past tense, or as "reed" implying present tense. Typical error rates when using HMMs in this fashion are usually below five percent. These techniques also work well for most European languages, although access to required training corpora is frequently difficult in these languages. Deciding how to convert numbers
DECtalk - Misplaced Pages Continue
4284-452: Is realized as /ˌklɪəɹˈʌʊt/ ). Likewise in French , many final consonants become no longer silent if followed by a word that begins with a vowel, an effect called liaison . This alternation cannot be reproduced by a simple word-concatenation system, which would require additional complexity to be context-sensitive . Formant synthesis does not use human speech samples at runtime. Instead,
4386-407: Is segmented into some or all of the following: individual phones , diphones , half-phones, syllables , morphemes , words , phrases , and sentences . Typically, the division into segments is done using a specially modified speech recognizer set to a "forced alignment" mode with some manual correction afterward, using visual representations such as the waveform and spectrogram . An index of
4488-522: Is stored by the program. Determining the correct pronunciation of each word is a matter of looking up each word in the dictionary and replacing the spelling with the pronunciation specified in the dictionary. The other approach is rule-based, in which pronunciation rules are applied to words to determine their pronunciations based on their spellings. This is similar to the "sounding out", or synthetic phonics , approach to learning reading. Each approach has advantages and drawbacks. The dictionary-based approach
4590-787: Is the NeXT -based system originally developed and marketed by Trillium Sound Research, a spin-off company of the University of Calgary , where much of the original research was conducted. Following the demise of the various incarnations of NeXT (started by Steve Jobs in the late 1980s and merged with Apple Computer in 1997), the Trillium software was published under the GNU General Public License, with work continuing as gnuspeech . The system, first marketed in 1994, provides full articulatory-based text-to-speech conversion using
4692-438: Is the ease with which the output is understood. The ideal speech synthesizer is both natural and intelligible. Speech synthesis systems usually try to maximize both characteristics. The two primary technologies generating synthetic speech waveforms are concatenative synthesis and formant synthesis . Each technology has strengths and weaknesses, and the intended uses of a synthesis system will typically determine which approach
4794-445: Is the partial or total inability of visual perception . In the absence of treatment such as corrective eyewear, assistive devices, and medical treatment, visual impairment may cause the individual difficulties with normal daily tasks, including reading and walking. The terms low vision and blindness are often used for levels of impairment which are difficult or impossible to correct and significantly impact daily life. In addition to
4896-622: Is to learn how to better project my voice" contains two pronunciations of "project". Most text-to-speech (TTS) systems do not generate semantic representations of their input texts, as processes for doing so are unreliable, poorly understood, and computationally ineffective. As a result, various heuristic techniques are used to guess the proper way to disambiguate homographs , like examining neighboring words and using statistics about frequency of occurrence. Recently TTS systems have begun to use HMMs (discussed above ) to generate " parts of speech " to aid in disambiguating homographs. This technique
4998-464: Is unfavorable. Therefore, early intervention is imperative for enabling successful psychological adjustment. Blindness can occur in combination with such conditions as intellectual disability , autism spectrum disorders , cerebral palsy , hearing impairments , and epilepsy . Blindness in combination with hearing loss is known as deafblindness . It has been estimated that over half of completely blind people have non-24-hour sleep–wake disorder ,
5100-566: Is used. Concatenative synthesis is based on the concatenation (stringing together) of segments of recorded speech. Generally, concatenative synthesis produces the most natural-sounding synthesized speech. However, differences between natural variations in speech and the nature of the automated techniques for segmenting the waveforms sometimes result in audible glitches in the output. There are three main sub-types of concatenative synthesis. Unit selection synthesis uses large databases of recorded speech. During database creation, each recorded utterance
5202-408: Is very common in English, yet is the only word in which the letter "f" is pronounced [v] .) As a result, nearly all speech synthesis systems use a combination of these approaches. Languages with a phonemic orthography have a very regular writing system, and the prediction of the pronunciation of words based on their spellings is quite successful. Speech synthesis systems for such languages often use
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#17327803893535304-446: Is very simple to implement, and has been in commercial use for a long time, in devices like talking clocks and calculators. The level of naturalness of these systems can be very high because the variety of sentence types is limited, and they closely match the prosody and intonation of the original recordings. Because these systems are limited by the words and phrases in their databases, they are not general-purpose and can only synthesize
5406-712: The German - Danish scientist Christian Gottlieb Kratzenstein won the first prize in a competition announced by the Russian Imperial Academy of Sciences and Arts for models he built of the human vocal tract that could produce the five long vowel sounds (in International Phonetic Alphabet notation: [aː] , [eː] , [iː] , [oː] and [uː] ). There followed the bellows -operated " acoustic-mechanical speech machine " of Wolfgang von Kempelen of Pressburg , Hungary, described in
5508-628: The HAL 9000 computer sings the same song as astronaut Dave Bowman puts it to sleep. Despite the success of purely electronic speech synthesis, research into mechanical speech-synthesizers continues. Linear predictive coding (LPC), a form of speech coding , began development with the work of Fumitada Itakura of Nagoya University and Shuzo Saito of Nippon Telegraph and Telephone (NTT) in 1966. Further developments in LPC technology were made by Bishnu S. Atal and Manfred R. Schroeder at Bell Labs during
5610-523: The developing world and are over the age of 50 years. Rates of visual impairment have decreased since the 1990s. Visual impairments have considerable economic costs both directly due to the cost of treatment and indirectly due to decreased ability to work. In 2010, the WHO definition for visual impairment was changed and now follows the ICD-11 . The previous definition which used "best corrected visual acuity"
5712-446: The emotion of a generated line using emotional contextualizers (a term coined by this project), a sentence or phrase that conveys the emotion of the take that serves as a guide for the model during inference. ElevenLabs is primarily known for its browser-based , AI-assisted text-to-speech software, Speech Synthesis, which can produce lifelike speech by synthesizing vocal emotion and intonation . The company states its software
5814-492: The formants (main bands of energy) with pure tone whistles. Deep learning speech synthesis uses deep neural networks (DNN) to produce artificial speech from text (text-to-speech) or spectrum (vocoder). The deep neural networks are trained using a large amount of recorded speech and, in the case of a text-to-speech system, the associated labels and/or input text. 15.ai uses a multi-speaker model —hundreds of voices are trained concurrently rather than sequentially, decreasing
5916-661: The 1970s. LPC was later the basis for early speech synthesizer chips, such as the Texas Instruments LPC Speech Chips used in the Speak & Spell toys from 1978. In 1975, Fumitada Itakura developed the line spectral pairs (LSP) method for high-compression speech coding, while at NTT. From 1975 to 1981, Itakura studied problems in speech analysis and synthesis based on the LSP method. In 1980, his team developed an LSP-based speech synthesizer chip. LSP
6018-691: The 1970s. One of the first was the Telesensory Systems Inc. (TSI) Speech+ portable calculator for the blind in 1976. Other devices had primarily educational purposes, such as the Speak & Spell toy produced by Texas Instruments in 1978. Fidelity released a speaking version of its electronic chess computer in 1979. The first video game to feature speech synthesis was the 1980 shoot 'em up arcade game , Stratovox (known in Japan as Speak & Rescue ), from Sun Electronics . The first personal computer game with speech synthesis
6120-729: The Aid to the Blind program in the Social Security Act passed in 1935. In 1972, the Aid to the Blind program and two others combined under Title XVI of the Social Security Act to form the Supplemental Security Income program which states: An individual shall be considered to be blind for purposes of this title if he has central visual acuity of 20/200 or less in the better eye with the use of
6222-636: The Bulgarians, the Byzantine Emperor Basil II blinded as many as 15,000 prisoners taken in the battle, before releasing them. Contemporary examples include the addition of methods such as acid throwing as a form of disfigurement . People with albinism often have vision loss to the extent that many are legally blind, though few of them actually cannot see. Leber congenital amaurosis can cause total blindness or severe sight loss from birth or early childhood. Retinitis pigmentosa
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#17327803893536324-559: The DECtalk Access32. Such implementations began as explorations into real-time software synthesis on general purpose CPUs, subsequently delivering a DECtalk Software product for Digital Unix and for Windows NT on Alpha and Intel processors. Certain versions of the synthesizer were prone to undesirable characteristics. For example, the alveolar stops were often assimilated as sounding more like dental stops . Also, versions such as Access32 would produce faint electronic beeps at
6426-472: The TTS system has been tuned. However, maximum naturalness typically require unit-selection speech databases to be very large, in some systems ranging into the gigabytes of recorded data, representing dozens of hours of speech. Also, unit selection algorithms have been known to select segments from a place that results in less than ideal synthesis (e.g. minor words become unclear) even when a better choice exists in
6528-517: The UK, the Certificate of Vision Impairment (CVI) is used to certify people as being severely sight impaired or sight impaired. The accompanying guidance for clinical staff states: "The National Assistance Act 1948 states that a person can be certified as severely sight impaired if they are 'so blind as to be unable to perform any work for which eye sight is essential'". Certification is based on whether
6630-717: The acoustic patterns of speech in the form of a spectrogram back into sound. Using this device, Alvin Liberman and colleagues discovered acoustic cues for the perception of phonetic segments (consonants and vowels). The first computer-based speech-synthesis systems originated in the late 1950s. Noriko Umeda et al. developed the first general English text-to-speech system in 1968, at the Electrotechnical Laboratory in Japan. In 1961, physicist John Larry Kelly, Jr and his colleague Louis Gerstman used an IBM 704 computer to synthesize speech, an event among
6732-561: The age of 40. Consequently, today cataracts are more common among adults than in children. That is, people face higher chances of developing cataracts as they age. Nonetheless, cataracts tend to have a greater financial and emotional toll upon children as they must undergo expensive diagnosis, long term rehabilitation, and visual assistance. Also, according to the Saudi Journal for Health Sciences, sometimes people experience irreversible amblyopia after pediatric cataract surgery because
6834-441: The cataracts prevented the normal maturation of vision prior to operation. Despite the great progress in treatment, cataracts remain a global problem in both economically developed and developing countries. At present, with the variant outcomes as well as the unequal access to cataract surgery, the best way to reduce the risk of developing cataracts is to avoid smoking and extensive exposure to sun light (i.e. UV-B rays). Glaucoma
6936-412: The combinations of words and phrases with which they have been preprogrammed. The blending of words within naturally spoken language however can still cause problems unless the many variations are taken into account. For example, in non-rhotic dialects of English the "r" in words like "clear" /ˈklɪə/ is usually only pronounced when the following word has a vowel as its first letter (e.g. "clear out"
7038-478: The database. Recently, researchers have proposed various automated methods to detect unnatural segments in unit-selection speech synthesis systems. Diphone synthesis uses a minimal speech database containing all the diphones (sound-to-sound transitions) occurring in a language. The number of diphones depends on the phonotactics of the language: for example, Spanish has about 800 diphones, and German about 2500. In diphone synthesis, only one example of each diphone
7140-410: The day. Blinding has been used as an act of vengeance and torture in some instances, to deprive a person of a major sense by which they can navigate or interact within the world, act fully independently, and be aware of events surrounding them. An example from the classical realm is Oedipus , who gouges out his own eyes after realizing that he fulfilled the awful prophecy spoken of him. Having crushed
7242-466: The developing world. The number of individuals blind from trachoma has decreased in the past 10 years from 6 million to 1.3 million, putting it in seventh place on the list of causes of blindness worldwide. Central corneal ulceration is also a significant cause of monocular blindness worldwide, accounting for an estimated 850,000 cases of corneal blindness every year in the Indian subcontinent alone. As
7344-543: The end of phrases. In the final years , early/mid-2000, the DECtalk IP was sold to Force Computers, Inc. In December 2001, the IP was sold from Force Computers, Inc, to Fonix Speech, Inc. (now SpeechFX, Inc. ), which offers DECtalk as a small-footprint TTS system and in a computer program form. The New York Times wrote: "like a scratchy recording of a person with a lisp" but added "usually understandable." DECtalk had
7446-457: The eye to the back of the brain, which can lead to decreased visual acuity. Cortical blindness results from injuries to the occipital lobe of the brain that prevent the brain from correctly receiving or interpreting signals from the optic nerve . Symptoms of cortical blindness vary greatly across individuals and may be more severe in periods of exhaustion or stress. It is common for people with cortical blindness to have poorer vision later in
7548-451: The following definition of blindness: Central visual acuity of 20/200 or less in the better eye with corrective glasses or central visual acuity of more than 20/200 if there is a visual field defect in which the peripheral field is contracted to such an extent that the widest diameter of the visual field subtends an angular distance no greater than 20 degrees in the better eye. The United States Congress included this definition as part of
7650-425: The greatest naturalness, because it applies only a small amount of digital signal processing (DSP) to the recorded speech. DSP often makes recorded speech sound less natural, although some systems use a small amount of signal processing at the point of concatenation to smooth the waveform. The output from the best unit-selection systems is often indistinguishable from real human voices, especially in contexts for which
7752-563: The human vocal tract and the articulation processes occurring there. The first articulatory synthesizer regularly used for laboratory experiments was developed at Haskins Laboratories in the mid-1970s by Philip Rubin , Tom Baer, and Paul Mermelstein. This synthesizer, known as ASY, was based on vocal tract models developed at Bell Laboratories in the 1960s and 1970s by Paul Mermelstein, Cecil Coker, and colleagues. Until recently, articulatory synthesis models have not been incorporated into commercial speech synthesis systems. A notable exception
7854-519: The leading causes of blindness in the developed world. Among working-age adults who are newly blind in England and Wales the most common causes in 2010 were: Cataracts are the greying or opacity of the crystalline lens, which can be caused in children by intrauterine infections, metabolic disorders, and genetically transmitted syndromes. Cataracts are the leading cause of child and adult blindness that doubles in prevalence with every ten years after
7956-419: The loss of one eye equals 25% impairment of the visual system and 24% impairment of the whole person; total loss of vision in both eyes is considered to be 100% visual impairment and 85% impairment of the whole person. Some people who fall into this category can use their considerable residual vision – their remaining sight – to complete daily tasks without relying on alternative methods. The role of
8058-539: The most common cause of blindness. Other disorders that may cause visual problems include age-related macular degeneration , diabetic retinopathy , corneal clouding , childhood blindness , and a number of infections . Visual impairment can also be caused by problems in the brain due to stroke , premature birth , or trauma, among others. These cases are known as cortical visual impairment . Screening for vision problems in children may improve future vision and educational achievement. Screening adults without symptoms
8160-526: The most prominent in the history of Bell Labs . Kelly's voice recorder synthesizer ( vocoder ) recreated the song " Daisy Bell ", with musical accompaniment from Max Mathews . Coincidentally, Arthur C. Clarke was visiting his friend and colleague John Pierce at the Bell Labs Murray Hill facility. Clarke was so impressed by the demonstration that he used it in the climactic scene of his screenplay for his novel 2001: A Space Odyssey , where
8262-531: The naturalness of the human voice. Examples of disadvantages of the method are low robustness when the data are not sufficient, lack of controllability and low performance in auto-regressive models. For tonal languages, such as Chinese or Taiwanese language, there are different levels of tone sandhi required and sometimes the output of speech synthesizer may result in the mistakes of tone sandhi. In 2023, VICE reporter Joseph Cox published findings that he had recorded five minutes of himself talking and then used
8364-411: The prognosis of eventual blindness are at comparatively high risk of suicide and thus may be in need of supportive services. Many studies have demonstrated how rapid acceptance of the serious visual impairment has led to a better, more productive compliance with rehabilitation programs. Moreover, psychological distress has been reported to be at its highest when sight loss is not complete, but the prognosis
8466-412: The pronunciation of a word based on its spelling , a process which is often called text-to-phoneme or grapheme -to-phoneme conversion ( phoneme is the term used by linguists to describe distinctive sounds in a language ). The simplest approach to text-to-phoneme conversion is the dictionary-based approach, where a large dictionary containing all the words of a language and their correct pronunciations
8568-454: The provision of technical aids. Low vision rehabilitation professionals, some of whom are connected to an agency for the blind, can provide advice on lighting and contrast to maximize remaining vision. These professionals also have access to non-visual aids, and can instruct patients in their uses. Older adults with visual impairment are at an increased risk of physical inactivity, slower gait speeds, and fear of falls. Physical activity
8670-403: The required training time and enabling the model to learn and generalize shared emotional context, even for voices with no exposure to such emotional context. The deep learning model used by the application is nondeterministic : each time that speech is generated from the same string of text, the intonation of the speech will be slightly different. The application also supports manually altering
8772-512: The robotic-sounding nature of formant synthesis, and has few of the advantages of either approach other than small size. As such, its use in commercial applications is declining, although it continues to be used in research because there are a number of freely available software implementations. An early example of Diphone synthesis is a teaching robot, Leachim , that was invented by Michael J. Freeman . Leachim contained information regarding class curricular and certain biographical information about
8874-524: The rule-based method extensively, resorting to dictionaries only for those few words, like foreign names and loanwords, whose pronunciations are not obvious from their spellings. On the other hand, speech synthesis systems for languages like English, which have extremely irregular spelling systems, are more likely to rely on dictionaries, and to use rule-based methods only for unusual words, or words that are not in their dictionaries. The consistent evaluation of speech synthesis systems may be difficult because of
8976-665: The same year. In 1976, Computalker Consultants released their CT-1 Speech Synthesizer. Designed by D. Lloyd Rice and Jim Cooper, it was an analog synthesizer built to work with microcomputers using the S-100 bus standard. Early electronic speech-synthesizers sounded robotic and were often barely intelligible. The quality of synthesized speech has steadily improved, but as of 2016 output from contemporary speech synthesis systems remains clearly distinguishable from actual human speech. Synthesized voices typically sounded male until 1990, when Ann Syrdal , at AT&T Bell Laboratories , created
9078-454: The students whom it was programmed to teach. It was tested in a fourth grade classroom in the Bronx, New York . Domain-specific synthesis concatenates prerecorded words and phrases to create complete utterances. It is used in applications where the variety of texts the system will output is limited to a particular domain, like transit schedule announcements or weather reports. The technology
9180-457: The substances formaldehyde and formic acid which in turn can cause blindness, an array of other health complications, and death. When competing with ethanol for metabolism, ethanol is metabolized first, and the onset of toxicity is delayed. Methanol is commonly found in methylated spirits , denatured ethyl alcohol , to avoid paying taxes on selling ethanol intended for human consumption. Methylated spirits are sometimes used by alcoholics as
9282-508: The symbolic linguistic representation into sound. In certain systems, this part includes the computation of the target prosody (pitch contour, phoneme durations), which is then imposed on the output speech. Long before the invention of electronic signal processing , some people tried to build machines to emulate human speech. Some early legends of the existence of " Brazen Heads " involved Pope Silvester II (d. 1003 AD), Albertus Magnus (1198–1280), and Roger Bacon (1214–1294). In 1779,
9384-563: The synthesized speech output is created using additive synthesis and an acoustic model ( physical modelling synthesis ). Parameters such as fundamental frequency , voicing , and noise levels are varied over time to create a waveform of artificial speech. This method is sometimes called rules-based synthesis ; however, many concatenative systems also have rules-based components. Many systems based on formant synthesis technology generate artificial, robotic-sounding speech that would never be mistaken for human speech. However, maximum naturalness
9486-405: The text into prosodic units , like phrases , clauses , and sentences . The process of assigning phonetic transcriptions to words is called text-to-phoneme or grapheme -to-phoneme conversion. Phonetic transcriptions and prosody information together make up the symbolic linguistic representation that is output by the front-end. The back-end—often referred to as the synthesizer —then converts
9588-462: The units could be used to automate various telephone-related tasks by handling both incoming and outgoing calls. This included acting as an interface to an email system and the capability to function as an alerting system by utilizing the ability to place calls and interact via touch tones with the person answering the phone. Later units were produced for PCs with ISA bus slots. In addition, various software implementations were produced, most notably
9690-447: The units in the speech database is then created based on the segmentation and acoustic parameters like the fundamental frequency ( pitch ), duration, position in the syllable, and neighboring phones. At run time , the desired target utterance is created by determining the best chain of candidate units from the database (unit selection). This process is typically achieved using a specially weighted decision tree . Unit selection provides
9792-399: The various permanent conditions, fleeting temporary vision impairment, amaurosis fugax , may occur, and may indicate serious medical problems. The most common causes of visual impairment globally are uncorrected refractive errors (43%), cataracts (33%), and glaucoma (2%). Refractive errors include near-sightedness , far-sightedness , presbyopia , and astigmatism . Cataracts are
9894-422: The visually impaired; 32.2% report depressive symptoms (12.01% in general population), and 15.61% report anxiety symptoms (10.69% in general population). The subjects making the most use of rehabilitation instruments, who lived alone, and preserved their own mobility and occupation were the least depressed, with the lowest risk of suicide and the highest level of social integration. Those with worsening sight and
9996-496: The vocoder, Homer Dudley developed a keyboard-operated voice-synthesizer called The Voder (Voice Demonstrator), which he exhibited at the 1939 New York World's Fair . Dr. Franklin S. Cooper and his colleagues at Haskins Laboratories built the Pattern playback in the late 1940s and completed it in 1950. There were several different versions of this hardware device; only one currently survives. The machine converts pictures of
10098-446: The word "in", and the address "12 St John St." uses the same abbreviation for both "Saint" and "Street". TTS systems with intelligent front ends can make educated guesses about ambiguous abbreviations, while others provide the same result in all cases, resulting in nonsensical (and sometimes comical) outputs, such as " Ulysses S. Grant " being rendered as "Ulysses South Grant". Speech synthesis systems use two basic approaches to determine
10200-586: The work done in the late 1970s for the Texas Instruments toy Speak & Spell , and in the early 1980s Sega arcade machines and in many Atari, Inc. arcade games using the TMS5220 LPC Chips . Creating proper intonation for these projects was painstaking, and the results have yet to be matched by real-time text-to-speech interfaces. Articulatory synthesis consists of computational techniques for synthesizing speech based on models of
10302-466: Was Manbiki Shoujo ( Shoplifting Girl ), released in 1980 for the PET 2001 , for which the game's developer, Hiroshi Suzuki, developed a " zero cross " programming technique to produce a synthesized speech waveform. Another early example, the arcade version of Berzerk , also dates from 1980. The Milton Bradley Company produced the first multi-player electronic game using voice synthesis, Milton , in
10404-400: Was changed to "presenting visual acuity". This change was made as newer studies showed that best-corrected vision overlooks a larger proportion of the population who has visual impairment due to uncorrected refractive errors, and/or lack of access to medical or surgical treatment. Distance vision impairment: Near vision impairment: Severely sight impaired Sight impaired Low vision In
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