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39-774: Amacher is a surname of German origin. Notable people with the surname include: Maryanne Amacher (1938–2009), American composer and installation artist Ryan C. Amacher (1945–2016), American economics professor, dean, and university president Rhein D. Amacher (1990-), German-American former collegiate NCAA Division I walk-on for the Oregon Ducks . References [ edit ] ^ Hanks, Patrick, ed. (2003). Dictionary of American Family Names . Vol. 1. New York: Oxford University Press. p. 31. ISBN   9780195081374 . OCLC   51655476 . [REDACTED] Surname list This page lists people with

78-411: A frequency-dependent absolute threshold of hearing (ATH) curve may be derived. Typically, the ear shows a peak of sensitivity (i.e., its lowest ATH) between 1–5 kHz , though the threshold changes with age, with older ears showing decreased sensitivity above 2 kHz. The ATH is the lowest of the equal-loudness contours . Equal-loudness contours indicate the sound pressure level (dB SPL), over

117-459: A long history in music theory and scientific research, and are still the object of disagreement and debate. In music, they are most commonly known by the name of 'combination tones', 'difference tones', and sometimes 'Tartini tones' (after the violinist Giuseppe Tartini , who is credited with discovering them). Amacher herself termed them 'ear tones' until 1992, when she discovered the work of David T. Kemp and Thomas Gold and began referring to them by

156-480: A lower priority to sounds outside the range of human hearing. By carefully shifting bits away from the unimportant components and toward the important ones, the algorithm ensures that the sounds a listener is most likely to perceive are most accurately represented. Psychoacoustics includes topics and studies that are relevant to music psychology and music therapy . Theorists such as Benjamin Boretz consider some of

195-413: A sharp clap of the hands might seem painfully loud in a quiet library but is hardly noticeable after a car backfires on a busy, urban street. This provides great benefit to the overall compression ratio, and psychoacoustic analysis routinely leads to compressed music files that are one-tenth to one-twelfth the size of high-quality masters, but with discernibly less proportional quality loss. Such compression

234-425: A signal and a masker are played together—for instance, when one person whispers while another person shouts—and the listener doesn't hear the weaker signal as it has been masked by the louder masker. Masking can also happen to a signal before a masker starts or after a masker stops. For example, a single sudden loud clap sound can make sounds inaudible that immediately precede or follow. The effects of backward masking

273-403: A sonic wrap, cascade inside ears, and out to space in front of their eyes ... Do not be alarmed! Your ears are not behaving strange or being damaged! ... these virtual tones are a natural and very real physical aspect of auditory perception , similar to the fusing of two images resulting in a third three dimensional image in binocular perception ... I want to release this music which is produced by

312-404: A work on sound environment "Close Up" for a 10-hour solo voice work for Cage "Empty Words" (1978). She also produced, alongside other works, "Torse" for Merce Cunningham from 1974 to 1980. Amacher worked extensively with a set of psychoacoustic phenomena known as 'auditory distortion products'; put simply: sounds generated inside the ear that are clearly audible to the hearer. These tones have

351-580: Is a feature of nearly all modern lossy audio compression formats. Some of these formats include Dolby Digital (AC-3), MP3 , Opus , Ogg Vorbis , AAC , WMA , MPEG-1 Layer II (used for digital audio broadcasting in several countries), and ATRAC , the compression used in MiniDisc and some Walkman models. Psychoacoustics is based heavily on human anatomy , especially the ear's limitations in perceiving sound as outlined previously. To summarize, these limitations are: A compression algorithm can assign

390-416: Is a specific frequency), humans tend to perceive that the pitch is f . An audible example can be found on YouTube. The psychoacoustic model provides for high quality lossy signal compression by describing which parts of a given digital audio signal can be removed (or aggressively compressed) safely—that is, without significant losses in the (consciously) perceived quality of the sound. It can explain how

429-464: Is advantageous to take into account not just the mechanics of the environment, but also the fact that both the ear and the brain are involved in a person's listening experience. The inner ear , for example, does significant signal processing in converting sound waveforms into neural stimuli, this processing renders certain differences between waveforms imperceptible. Data compression techniques, such as MP3 , make use of this fact. In addition,

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468-755: Is different from Wikidata All set index articles Maryanne Amacher Amacher was born in Kane, Pennsylvania , to an American nurse and a Swiss freight train worker. An only child, she grew up playing the piano. Amacher left Kane to attend the University of Pennsylvania on a full scholarship where she received a B.F.A in 1964. While there she studied composition with George Rochberg and Karlheinz Stockhausen . She also studied composition in Salzburg, Austria, and Dartington, England. Subsequently, she did graduate work in acoustics and computer science at

507-438: Is not a purely mechanical phenomenon of wave propagation , but is also a sensory and perceptual event. When a person hears something, that something arrives at the ear as a mechanical sound wave traveling through the air, but within the ear it is transformed into neural action potentials . These nerve pulses then travel to the brain where they are perceived. Hence, in many problems in acoustics, such as for audio processing , it

546-406: Is not directly coupled with frequency range. Frequency resolution of the ear is about 3.6 Hz within the octave of 1000–2000 Hz That is, changes in pitch larger than 3.6 Hz can be perceived in a clinical setting. However, even smaller pitch differences can be perceived through other means. For example, the interference of two pitches can often be heard as a repetitive variation in

585-425: Is the branch of psychophysics involving the scientific study of the perception of sound by the human auditory system . It is the branch of science studying the psychological responses associated with sound including noise , speech , and music . Psychoacoustics is an interdisciplinary field including psychology, acoustics , electronic engineering, physics, biology, physiology, and computer science. Hearing

624-469: Is therefore defined as 0  dB , but the upper limit is not as clearly defined. The upper limit is more a question of the limit where the ear will be physically harmed or with the potential to cause noise-induced hearing loss . A more rigorous exploration of the lower limits of audibility determines that the minimum threshold at which a sound can be heard is frequency dependent. By measuring this minimum intensity for testing tones of various frequencies,

663-446: Is weaker than forward masking. The masking effect has been widely studied in psychoacoustical research. One can change the level of the masker and measure the threshold, then create a diagram of a psychophysical tuning curve that will reveal similar features. Masking effects are also used in lossy audio encoding, such as MP3 . When presented with a harmonic series of frequencies in the relationship 2 f , 3 f , 4 f , 5 f , etc. (where f

702-507: The University of Illinois at Urbana-Champaign . While in residence at the University of Buffalo , in 1967, she created City Links: Buffalo , a 28-hour piece using 5 microphones in different parts of the city, broadcast live by radio station WBFO . There were 21 other pieces in the "City Links" series, and more information can be found in the brochure for an exhibition on the series by Ludlow 38 in NYC (available on their website). A common feature

741-504: The surname Amacher . If an internal link intending to refer to a specific person led you to this page, you may wish to change that link by adding the person's given name (s) to the link. Retrieved from " https://en.wikipedia.org/w/index.php?title=Amacher&oldid=1191156440 " Categories : Surnames of German origin Surnames Hidden categories: Articles with short description Short description

780-603: The "Mini-Sound Series" (1985– ) a new multimedia form she created that is unique in its use of architecture and serialized narrative. She was invited while doing a fellowship at the Harvard University and the Massachusetts Institute of Technology by John Cage to work on several projects. The collaboration resulted with a storm soundtrack for Cage's multimedia "Lecture on the Weather" (1975) and

819-419: The dark. Suppose a listener can hear a given acoustical signal under silent conditions. When a signal is playing while another sound is being played (a masker), the signal has to be stronger for the listener to hear it. The masker does not need to have the frequency components of the original signal for masking to happen. A masked signal can be heard even though it is weaker than the masker. Masking happens when

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858-503: The ear has a nonlinear response to sounds of different intensity levels; this nonlinear response is called loudness . Telephone networks and audio noise reduction systems make use of this fact by nonlinearly compressing data samples before transmission and then expanding them for playback. Another effect of the ear's nonlinear response is that sounds that are close in frequency produce phantom beat notes, or intermodulation distortion products. The human ear can nominally hear sounds in

897-443: The first packet-switched network . Licklider wrote a paper entitled "A duplex theory of pitch perception". Psychoacoustics is applied within many fields of software development, where developers map proven and experimental mathematical patterns in digital signal processing. Many audio compression codecs such as MP3 and Opus use a psychoacoustic model to increase compression ratios. The success of conventional audio systems for

936-467: The head, as though there were a 'tiny loudspeaker inside the ear'. Amacher was the first to systematically explore the musical use of these phenomena using electroacoustic sound technologies. The subtitle of her first Tzadik Records album Sound Characters (Making the Third Ear) is a reference to them. She describes the subjective experience of these phenomena in the following passage: When played at

975-478: The high-frequency end, but nearly linear at the low-frequency end. The intensity range of audible sounds is enormous. Human eardrums are sensitive to variations in sound pressure and can detect pressure changes from as small as a few micropascals (μPa) to greater than 100  kPa . For this reason, sound pressure level is also measured logarithmically, with all pressures referenced to 20 μPa (or 1.973 85 × 10   atm ). The lower limit of audibility

1014-652: The listener ... Over the years she received several major commissions in the United States and Europe with occasional work in Asia and Central and South America. Amacher received a 1998 Foundation for Contemporary Arts Grants to Artists Award. In 2005, she was awarded the Prix Ars Electronica (the Golden Nica) in the "Digital Musics" category for her project "TEO! A sonic sculpture" . In 2009 she

1053-438: The need for spatial audio and in sonification computer games and other applications, such as drone flying and image-guided surgery . It is also applied today within music, where musicians and artists continue to create new auditory experiences by masking unwanted frequencies of instruments, causing other frequencies to be enhanced. Yet another application is in the design of small or lower-quality loudspeakers, which can use

1092-464: The process in 1956 to obtain a new set of equal-loudness curves for a frontal sound source measured in an anechoic chamber . The Robinson-Dadson curves were standardized as ISO 226 in 1986. In 2003, ISO 226 was revised as equal-loudness contour using data collected from 12 international studies. Sound localization is the process of determining the location of a sound source. The brain utilizes subtle differences in loudness, tone and timing between

1131-446: The psychoacoustical terminology of 'otoacoustic emissions'. It has since become clear that some of the sounds Amacher, and indeed all musicians who have exploited this phenomenon, were generating can be attributed to a particular family of otoacoustic emissions known as 'distortion product otoacoustic emissions' (DPOAE). Occurring in response to two pure tones presented simultaneously to the ear, these tones appear to localise in or around

1170-528: The range 20 to 20 000   Hz . The upper limit tends to decrease with age; most adults are unable to hear above 16 000  Hz . The lowest frequency that has been identified as a musical tone is 12 Hz under ideal laboratory conditions. Tones between 4 and 16 Hz can be perceived via the body's sense of touch . Human perception of audio signal time separation has been measured to be less than 10 microseconds. This does not mean that frequencies above 100 kHz are audible, but that time discrimination

1209-484: The range of audible frequencies, that are perceived as being of equal loudness. Equal-loudness contours were first measured by Fletcher and Munson at Bell Labs in 1933 using pure tones reproduced via headphones, and the data they collected are called Fletcher–Munson curves . Because subjective loudness was difficult to measure, the Fletcher–Munson curves were averaged over many subjects. Robinson and Dadson refined

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1248-527: The reproduction of music in theatres and homes can be attributed to psychoacoustics and psychoacoustic considerations gave rise to novel audio systems, such as psychoacoustic sound field synthesis . Furthermore, scientists have experimented with limited success in creating new acoustic weapons, which emit frequencies that may impair, harm, or kill. Psychoacoustics are also leveraged in sonification to make multiple independent data dimensions audible and easily interpretable. This enables auditory guidance without

1287-546: The results of psychoacoustics to be meaningful only in a musical context. Irv Teibel 's Environments series LPs (1969–79) are an early example of commercially available sounds released expressly for enhancing psychological abilities. Psychoacoustics has long enjoyed a symbiotic relationship with computer science . Internet pioneers J. C. R. Licklider and Bob Taylor both completed graduate-level work in psychoacoustics, while BBN Technologies originally specialized in consulting on acoustics issues before it began building

1326-441: The right sound level, which is quite high and exciting, the tones in this music will cause your ears to act as neurophonic instruments that emit sounds that will seem to be issuing directly from your head ... (my audiences) discover they are producing a tonal dimension of the music which interacts melodically, rhythmically, and spatially with the tones in the room. Tones 'dance' in the immediate space of their body, around them like

1365-399: The space or speakers facing at the walls or floors) she would create the psychoacoustic illusions of sound shapes or "presence". Amacher's early work is best represented in three series of multimedia installations produced in the United States, Europe, and Japan: the sonic telepresence series, "City Links 1–22" (1967– ); the architecturally staged "Music for Sound-Joined Rooms" (1980– ); and

1404-574: The two ears to allow us to localize sound sources. Localization can be described in terms of three-dimensional position: the azimuth or horizontal angle, the zenith or vertical angle, and the distance (for static sounds) or velocity (for moving sounds). Humans, as most four-legged animals , are adept at detecting direction in the horizontal, but less so in the vertical directions due to the ears being placed symmetrically. Some species of owls have their ears placed asymmetrically and can detect sound in all three planes, an adaption to hunt small mammals in

1443-582: The volume of the tone. This amplitude modulation occurs with a frequency equal to the difference in frequencies of the two tones and is known as beating . The semitone scale used in Western musical notation is not a linear frequency scale but logarithmic . Other scales have been derived directly from experiments on human hearing perception, such as the mel scale and Bark scale (these are used in studying perception, but not usually in musical composition), and these are approximately logarithmic in frequency at

1482-907: Was invited for Brückenmusik, Cologne. At the time of her death she had been working three years on a 40-channel piece commissioned by the Experimental Media and Performing Arts Center in Troy, New York. Maryanne Amacher has been an important influence for composers such as Rhys Chatham and Thurston Moore . For the last decade of her life she taught at the Bard College MFA program. In 2020, The Music and Recorded Sound Division of The New York Public Library acquired Amacher's archives. Multimedia Installations (all works in progress) Dance Scores (all choreography Merce Cunningham ) Works for Tape (unless otherwise noted) Events : Psychoacoustic Psychoacoustics

1521-665: Was the use of dedicated, FM radio quality telephone (0–15,000 Hz range) lines to connect the sound environments of different sites into the same space, a very early example of what is now called " telematic performance " which preceded much more famous examples by Max Neuhaus , amongst others. (Neuhaus himself was involved with the original 1967 work in Buffalo.) Her major pieces have almost exclusively been site-specific, often using many loudspeakers to create what she called "structure borne sound", differentiating it from "airborne sound". By using many diffuse sound sources (either not in

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