Holophonics
Encyclopedia
Holophonics is a binaural recording
system created by Hugo Zuccarelli that is claimed to be based on the (unsupported) claim that the auditory system acts as an interferometer
. The sound characteristics of Holophonics are most clearly heard through headphones
, though can be demonstrated to be effective with 2 channel stereo speakers, as long as they are phase coherent. Zuccarelli's company, Acoustic Integrity, also sells loudspeakers under the Holophonics brand.
There has been some controversy over the claims made by Hugo Zucharelli regarding this recording technique. The effects achieved are comparable to traditional binaural recording
using mannequin heads, or via more traditional 3D audio techniques via HRTF's. There is no evidence nor studies conducted that indicate that the Holophonic technique is substantially different from or superior to these methods, nor has Zucharelli ever published his technique, nor has he allowed independent study of the results. The only available publication is a patent, which describes a fairly typical dummy-head binaural recording
.
While otoacoustic emissions do exist, there is no evidence to support the assertion that these play a role in sound localization, nor is any mechanism for this "interference" effect claimed by Zucharelli supported. On the contrary, there is abundant literature proving that properly presented spatial cues via HRTF synthesis (mimicking binaural heads) or binaural recording is adequate to reproduce realistic spatial recordings comparable to real listening, and comparable to the Holophonics demonstrations.
Hugo Zuccarelli in 1980, during his studies at the Politecnico di Milano university. In 1983 Zuccarelli released a recording entitled Zuccarelli Holophonics (The Matchbox Shaker) the UK by CBS which consisted entirely of short recordings of sound effects designed to show off the system. These included the shaking matchbox, haircut & blower, bees, balloon, plastic bag, birds, airplanes, fireworks, thunder, and racing cars. In its early years, Holophonics was used by various artists including Pink Floyd (The Final Cut, 1984), Roger Waters solo album (The Pros and Cons..., 1985), Psychic TV (Dreams Less Sweet, 1983). It has been used in film soundtrack, popular music, television and themeparks.
Zuccarelli states that the human auditory system is a sound emitter, producing a reference sound that combines with incoming sound to form an interference pattern inside the ear. The nature of this pattern is sensitive to the direction of the incoming sound. According to the hypothesis, the cochlea detects and analyzes this pattern as if it were an acoustic hologram. The brain then interprets this data and infers the direction of the sound. An article from Zuccarelli presenting this theory was printed in the magazine New Scientist
in 1983. This article was soon followed by two letters, casting doubt on Zuccarelli's theory and his scientific abilities.
To date, there is no evidence whatsoever that any acoustic emissions are used for sound localization. Holophonics, like binaural recording
, instead reproduces the interaural differences (arrival time and amplitude between the ears), as well as rudimentary head-related transfer function
s (HRTF). These create the illusion that sounds produced in the membrane of a speaker emanate from specific directions.
Binaural recording
Binaural recording is a method of recording sound that uses two microphones, arranged with the intent to create a 3-D stereo sound sensation for the listener of actually being in the room with the performers or instruments. This effect is often created using a technique known as "Dummy head...
system created by Hugo Zuccarelli that is claimed to be based on the (unsupported) claim that the auditory system acts as an interferometer
Interferometry
Interferometry refers to a family of techniques in which electromagnetic waves are superimposed in order to extract information about the waves. An instrument used to interfere waves is called an interferometer. Interferometry is an important investigative technique in the fields of astronomy,...
. The sound characteristics of Holophonics are most clearly heard through headphones
Headphones
Headphones are a pair of small loudspeakers, or less commonly a single speaker, held close to a user's ears and connected to a signal source such as an audio amplifier, radio, CD player or portable Media Player. They are also known as stereophones, headsets or, colloquially, cans. The in-ear...
, though can be demonstrated to be effective with 2 channel stereo speakers, as long as they are phase coherent. Zuccarelli's company, Acoustic Integrity, also sells loudspeakers under the Holophonics brand.
There has been some controversy over the claims made by Hugo Zucharelli regarding this recording technique. The effects achieved are comparable to traditional binaural recording
Binaural recording
Binaural recording is a method of recording sound that uses two microphones, arranged with the intent to create a 3-D stereo sound sensation for the listener of actually being in the room with the performers or instruments. This effect is often created using a technique known as "Dummy head...
using mannequin heads, or via more traditional 3D audio techniques via HRTF's. There is no evidence nor studies conducted that indicate that the Holophonic technique is substantially different from or superior to these methods, nor has Zucharelli ever published his technique, nor has he allowed independent study of the results. The only available publication is a patent, which describes a fairly typical dummy-head binaural recording
Binaural recording
Binaural recording is a method of recording sound that uses two microphones, arranged with the intent to create a 3-D stereo sound sensation for the listener of actually being in the room with the performers or instruments. This effect is often created using a technique known as "Dummy head...
.
While otoacoustic emissions do exist, there is no evidence to support the assertion that these play a role in sound localization, nor is any mechanism for this "interference" effect claimed by Zucharelli supported. On the contrary, there is abundant literature proving that properly presented spatial cues via HRTF synthesis (mimicking binaural heads) or binaural recording is adequate to reproduce realistic spatial recordings comparable to real listening, and comparable to the Holophonics demonstrations.
History
Holophonics was created by ArgentineArgentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
Hugo Zuccarelli in 1980, during his studies at the Politecnico di Milano university. In 1983 Zuccarelli released a recording entitled Zuccarelli Holophonics (The Matchbox Shaker) the UK by CBS which consisted entirely of short recordings of sound effects designed to show off the system. These included the shaking matchbox, haircut & blower, bees, balloon, plastic bag, birds, airplanes, fireworks, thunder, and racing cars. In its early years, Holophonics was used by various artists including Pink Floyd (The Final Cut, 1984), Roger Waters solo album (The Pros and Cons..., 1985), Psychic TV (Dreams Less Sweet, 1983). It has been used in film soundtrack, popular music, television and themeparks.
Zuccarelli states that the human auditory system is a sound emitter, producing a reference sound that combines with incoming sound to form an interference pattern inside the ear. The nature of this pattern is sensitive to the direction of the incoming sound. According to the hypothesis, the cochlea detects and analyzes this pattern as if it were an acoustic hologram. The brain then interprets this data and infers the direction of the sound. An article from Zuccarelli presenting this theory was printed in the magazine New Scientist
New Scientist
New Scientist is a weekly non-peer-reviewed English-language international science magazine, which since 1996 has also run a website, covering recent developments in science and technology for a general audience. Founded in 1956, it is published by Reed Business Information Ltd, a subsidiary of...
in 1983. This article was soon followed by two letters, casting doubt on Zuccarelli's theory and his scientific abilities.
To date, there is no evidence whatsoever that any acoustic emissions are used for sound localization. Holophonics, like binaural recording
Binaural recording
Binaural recording is a method of recording sound that uses two microphones, arranged with the intent to create a 3-D stereo sound sensation for the listener of actually being in the room with the performers or instruments. This effect is often created using a technique known as "Dummy head...
, instead reproduces the interaural differences (arrival time and amplitude between the ears), as well as rudimentary head-related transfer function
Head-related transfer function
A head-related transfer function is a response that characterizes how an ear receives a sound from a point in space; a pair of HRTFs for two ears can be used to synthesize a binaural sound that seems to come from a particular point in space. Some consumer home entertainment products designed to...
s (HRTF). These create the illusion that sounds produced in the membrane of a speaker emanate from specific directions.
Recordings released using holophonics
- Pink FloydPink FloydPink Floyd were an English rock band that achieved worldwide success with their progressive and psychedelic rock music. Their work is marked by the use of philosophical lyrics, sonic experimentation, innovative album art, and elaborate live shows. Pink Floyd are one of the most commercially...
, "The Final CutThe Final Cut (album)The Final Cut is the twelfth studio album by English progressive rock group Pink Floyd. It was released in March 1983 by Harvest Records in the United Kingdom, and several weeks later by Columbia Records in the United States. A concept album, The Final Cut is the last of the band's releases to...
" Harvest/E.M.I, 7243 8 31242 2 0 (1982). - Roger WatersRoger WatersGeorge Roger Waters is an English musician, singer-songwriter and composer. He was a founding member of the progressive rock band Pink Floyd, serving as bassist and co-lead vocalist. Following the departure of bandmate Syd Barrett in 1968, Waters became the band's lyricist, principal songwriter...
, "The Pros and Cons of Hitchhiking", Harvest, CDP 7 46029 2 (1984). - Psychic TVPsychic TVPsychic TV or PTV, is a video art and music group that primarily performs psychedelic, punk, electronic and experimental music...
, "Dreams Less SweetDreams Less SweetDreams Less Sweet is the second proper album by Psychic TV. The album was released in Holophonic sound.-1983 12" vinyl pressing:Side A:#"Hymn 23"#*Synthesizer : Andrew Poppy#"The Orchids"#*Oboe: Jessica Ilbert#"Botanica"#"Iron Glove"...
", Some Bizarre (1983).