![Feedback loop block diagram](https://upload.wikimedia.org/wikipedia/commons/0/02/Feedback_loop_block_diagram.png)
Audio feedback (also known as acoustic feedback, simply as feedback) is a
positive feedback
Positive feedback (exacerbating feedback, self-reinforcing feedback) is a process that occurs in a feedback loop which exacerbates the effects of a small disturbance. That is, the effects of a perturbation on a system include an increase in th ...
situation which may occur when an acoustic path exists between an audio input (for example, a
microphone
A microphone, colloquially called a mic or mike (), is a transducer that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and publ ...
or
guitar pickup
A pickup is a transducer that captures or senses mechanical vibrations produced by musical instruments, particularly stringed instruments such as the electric guitar, and converts these to an electrical signal that is amplified using an instru ...
) and an audio output (for example, a
loudspeaker
A loudspeaker (commonly referred to as a speaker or speaker driver) is an electroacoustic transducer that converts an electrical audio signal into a corresponding sound. A ''speaker system'', also often simply referred to as a "speaker" or ...
). In this example, a signal received by the microphone is
amplified and passed out of the loudspeaker. The sound from the loudspeaker can then be received by the microphone again, amplified further, and then passed out through the loudspeaker again. The
frequency
Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ...
of the resulting howl is determined by resonance frequencies in the microphone, amplifier, and loudspeaker, the acoustics of the room, the directional pick-up and emission patterns of the microphone and loudspeaker, and the distance between them. The principles of audio feedback were first discovered by Danish scientist
Søren Absalon Larsen, hence it is also known as the Larsen effect.
Feedback is almost always considered undesirable when it occurs with a singer's or public speaker's microphone at an event using a
sound reinforcement system
A sound reinforcement system is the combination of microphones, signal processors, amplifiers, and loudspeakers in enclosures all controlled by a mixing console that makes live or pre-recorded sounds louder and may also distribute those sou ...
or
PA system
A public address system (or PA system) is an electronic system comprising microphones, amplifiers, loudspeakers, and related equipment. It increases the apparent volume (loudness) of a human voice, musical instrument, or other acoustic sound sou ...
.
Audio engineer
An audio engineer (also known as a sound engineer or recording engineer) helps to produce a recording or a live performance, balancing and adjusting sound sources using equalization, dynamics processing and audio effects, mixing, reproduction ...
s typically use directional microphones with
cardioid
In geometry, a cardioid () is a plane curve traced by a point on the perimeter of a circle that is rolling around a fixed circle of the same radius. It can also be defined as an epicycloid having a single cusp. It is also a type of sinusoidal ...
pickup patterns and various electronic devices, such as
equalizers and, since the 1990s, automatic
feedback suppressor
A feedback suppressor is an audio signal processing device which is used in the signal path in a live sound reinforcement system to prevent or suppress audio feedback.
Digital feedback reduction is the application of digital techniques to sound r ...
s, to prevent feedback, which detracts from the audience's enjoyment of the event and may damage equipment or
hearing
Hearing, or auditory perception, is the ability to perceive sounds through an organ, such as an ear, by detecting vibrations as periodic changes in the pressure of a surrounding medium. The academic field concerned with hearing is audit ...
.
Since the 1960s,
electric guitar
An electric guitar is a guitar that requires external amplification in order to be heard at typical performance volumes, unlike a standard acoustic guitar (however combinations of the two - a semi-acoustic guitar and an electric acoustic gu ...
players in
rock music
Rock music is a broad genre of popular music that originated as " rock and roll" in the United States in the late 1940s and early 1950s, developing into a range of different styles in the mid-1960s and later, particularly in the United States a ...
bands using loud
guitar amplifier
A guitar amplifier (or amp) is an electronic device or system that strengthens the electrical signal from a pickup on an electric guitar, bass guitar, or acoustic guitar so that it can produce sound through one or more loudspeakers, which a ...
s,
speaker cabinets
A loudspeaker enclosure or loudspeaker cabinet is an enclosure (often rectangular box-shaped) in which speaker drivers (e.g., loudspeakers and tweeters) and associated electronic hardware, such as crossover circuits and, in some cases, power ...
and
distortion
In signal processing, distortion is the alteration of the original shape (or other characteristic) of a signal. In communications and electronics it means the alteration of the waveform of an information-bearing signal, such as an audio signal ...
effects have intentionally created guitar feedback to create different sounds including long sustained tones that cannot be produced using standard playing techniques. The sound of guitar feedback is considered to be a desirable musical effect in
heavy metal music
Heavy metal (or simply metal) is a genre of rock music that developed in the late 1960s and early 1970s, largely in the United Kingdom and United States. With roots in blues rock, psychedelic rock and acid rock, heavy metal bands developed a ...
,
hardcore punk
Hardcore punk (also known as simply hardcore) is a punk rock music genre and subculture that originated in the late 1970s. It is generally faster, harder, and more aggressive than other forms of punk rock. Its roots can be traced to earlier punk ...
and
grunge
Grunge (sometimes referred to as the Seattle sound) is an alternative rock genre and subculture that emerged during the in the American Pacific Northwest state of Washington, particularly in Seattle and nearby towns. Grunge fuses elements of p ...
.
Jimi Hendrix
James Marshall "Jimi" Hendrix (born Johnny Allen Hendrix; November 27, 1942September 18, 1970) was an American guitarist, singer and songwriter. Although his mainstream career spanned only four years, he is widely regarded as one of the most ...
was an innovator in the intentional use of guitar feedback in his
guitar solo
A guitar solo is a melodic passage, instrumental section, or entire piece of music, pre-written (or improvised) to be played on a classical guitar, electric guitar or an acoustic guitar. In 20th and 21st century traditional music and popular m ...
s to create unique musical sounds.
History and theory
The conditions for feedback follow the
Barkhausen stability criterion
In electronics, the Barkhausen stability criterion is a mathematical condition to determine when a linear electronic circuit will oscillate. It was put forth in 1921 by German physicist Heinrich Georg Barkhausen (1881–1956). It is widely u ...
, namely that, with sufficiently high gain, a stable
oscillation
Oscillation is the repetitive or periodic variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. Familiar examples of oscillation include a swinging pendulum ...
can (and usually will) occur in a feedback loop whose frequency is such that the phase delay is an
integer
An integer is the number zero (), a positive natural number (, , , etc.) or a negative integer with a minus sign (−1, −2, −3, etc.). The negative numbers are the additive inverses of the corresponding positive numbers. In the language ...
multiple of 360
degree
Degree may refer to:
As a unit of measurement
* Degree (angle), a unit of angle measurement
** Degree of geographical latitude
** Degree of geographical longitude
* Degree symbol (°), a notation used in science, engineering, and mathematics
...
s and the
gain
Gain or GAIN may refer to:
Science and technology
* Gain (electronics), an electronics and signal processing term
* Antenna gain
* Gain (laser), the amplification involved in laser emission
* Gain (projection screens)
* Information gain in de ...
at that frequency is equal to 1. If the small-signal gain is greater than 1 for some frequency then the system will start to oscillate at that frequency because noise at that frequency will be amplified. Sound will be produced without anyone actually playing. The sound level will increase until the output starts
clipping
Clipping may refer to:
Words
* Clipping (morphology), the formation of a new word by shortening it, e.g. "ad" from "advertisement"
* Clipping (phonetics), shortening the articulation of a speech sound, usually a vowel
* Clipping (publications) ...
, reducing the loop gain to exactly unity. This is the principle upon which
electronic oscillator
An electronic oscillator is an electronic circuit that produces a periodic, oscillation, oscillating electronic signal, often a sine wave or a square wave or a triangle wave. Oscillation, Oscillators convert direct current (DC) from a power supp ...
s are based; in that case, although the feedback loop is purely electronic, the principle is the same. If the gain is large but slightly less than 1, then
ringing
Ringing may mean:
Vibrations
* Ringing (signal), unwanted oscillation of a signal, leading to ringing artifacts
* Vibration of a harmonic oscillator
** Bell ringing
* Ringing (telephony), the sound of a telephone bell
* Ringing (medicine), a ri ...
will be introduced, but only when at least some input sound is already being sent through the system.
Early academic work on acoustical feedback was done by Dr.
C. Paul Boner. Boner was responsible for establishing basic theories of acoustic feedback, room-ring modes, and room-sound system equalizing techniques. Boner reasoned that when feedback happened, it did so at one precise frequency. He also reasoned that it could be stopped by inserting a very narrow
notch filter
In signal processing, a band-stop filter or band-rejection filter is a filter that passes most frequencies unaltered, but attenuates those in a specific range to very low levels. It is the opposite of a band-pass filter. A notch filter is a ...
at that frequency in the loudspeaker's
signal chain
Signal chain, or signal-processing chain is a term used in signal processing and mixed-signal system design to describe a series of signal-conditioning electronic components that receive input (data acquired from sampling either real-time phenom ...
. He worked with
Gifford White, founder of
White Instruments to hand craft notch filters for specific feedback frequencies in specific rooms.
Distance
To maximize
gain before feedback
In live sound mixing, gain before feedback (GBF) is a practical measure of how much a microphone can be amplified in a sound reinforcement system before causing audio feedback. In audiology, GBF is a measure of hearing aid performance. In both fie ...
, the amount of sound energy that is fed back to the microphones must be reduced as much as is practical. As sound pressure falls off with 1/r with respect to the distance r in free space, or up to a distance known as reverberation distance in closed spaces (and the energy density with 1/r²), it is important to keep the microphones at a large enough distance from the speaker systems. As well, microphones should not be positioned in front of speakers and individuals using mics should be asked to avoid pointing the microphone at speaker enclosures.
Directivity
Additionally, the loudspeakers and microphones should have non-uniform
directivity and should stay out of the maximum
sensitivity of each other, ideally in a direction of cancellation.
Public address speakers often achieve directivity in the mid and treble region (and good
efficiency) via horn systems. Sometimes the woofers have a
cardioid
In geometry, a cardioid () is a plane curve traced by a point on the perimeter of a circle that is rolling around a fixed circle of the same radius. It can also be defined as an epicycloid having a single cusp. It is also a type of sinusoidal ...
characteristic.
Professional setups circumvent feedback by placing the main speakers away from the band or artist, and then having several smaller speakers known as
''monitors'' pointing back at each band member, but in the opposite direction to that in which the microphones are pointing taking advantage of microphones with a
cardioid pickup pattern which are common in sound reinforcement applications. This configuration reducees the opportunities for feedback and allows independent control of the sound pressure levels for the audience and the performers.
Frequency response
Almost always, the natural frequency responses of
sound reinforcement system
A sound reinforcement system is the combination of microphones, signal processors, amplifiers, and loudspeakers in enclosures all controlled by a mixing console that makes live or pre-recorded sounds louder and may also distribute those sou ...
s is not ideally flat. This leads to acoustical feedback at the frequency with the highest loop gain, which may be much higher than the average gain over all frequencies (
resonance
Resonance describes the phenomenon of increased amplitude that occurs when the frequency of an applied periodic force (or a Fourier component of it) is equal or close to a natural frequency of the system on which it acts. When an oscillatin ...
). It is therefore helpful to apply some form of
equalization to reduce the gain of this frequency.
Feedback can be reduced manually by "
ringing out" a sound system prior to a performance. The sound engineer can increase the level of a microphone or guitar pickup until feedback occurs. The engineer can then attenuate the relevant frequency on an equalizer preventing feedback at that frequency but allowing sufficient volume at other frequencies. Many professional sound engineers can identify feedback frequencies by ear but others use a real time analyzer to identify the ringing frequency.
To avoid feedback, automatic anti-feedback devices can be used. (In the marketplace these go by the name "feedback destroyer" or "feedback eliminator".) Some of these work by shifting the frequency slightly, with this upshift resulting in a "chirp"-sound instead of a howling sound of unaddressed feedback. Other devices use sharp notch-filters to filter out offending frequencies. Adaptive algorithms are often used to automatically tune these notch filters.
Deliberate uses
![Jimi Hendrix 1967 uncropped](https://upload.wikimedia.org/wikipedia/commons/a/af/Jimi_Hendrix_1967_uncropped.jpg)
To intentionally create feedback, an
electric guitar
An electric guitar is a guitar that requires external amplification in order to be heard at typical performance volumes, unlike a standard acoustic guitar (however combinations of the two - a semi-acoustic guitar and an electric acoustic gu ...
player needs a
guitar amplifier
A guitar amplifier (or amp) is an electronic device or system that strengthens the electrical signal from a pickup on an electric guitar, bass guitar, or acoustic guitar so that it can produce sound through one or more loudspeakers, which a ...
and a loudspeaker
cabinet
Cabinet or The Cabinet may refer to:
Furniture
* Cabinetry, a box-shaped piece of furniture with doors and/or drawers
* Display cabinet, a piece of furniture with one or more transparent glass sheets or transparent polycarbonate sheets
* Filing ...
, with very high gain (amplification) and/or the guitar brought near the speaker. The guitarist then allows the open strings to vibrate freely and brings the guitar close to the
speaker enclosure
A loudspeaker enclosure or loudspeaker cabinet is an enclosure (often rectangular box-shaped) in which speaker drivers (e.g., loudspeakers and tweeters) and associated electronic hardware, such as crossover circuits and, in some cases, power ...
of the guitar amp. The use of
distortion
In signal processing, distortion is the alteration of the original shape (or other characteristic) of a signal. In communications and electronics it means the alteration of the waveform of an information-bearing signal, such as an audio signal ...
effects unit
An effects unit or effects pedal is an electronic device that alters the sound of a musical instrument or other audio source through audio signal processing.
Common effects include distortion/overdrive, often used with electric guitar in el ...
s also facilitates the creation of intentional feedback.
Early examples in popular music
A deliberate use of acoustic feedback was pioneered by
blues
Blues is a music genre and musical form which originated in the Deep South of the United States around the 1860s. Blues incorporated spirituals, work songs, field hollers, shouts, chants, and rhymed simple narrative ballads from the Afr ...
and
rock 'n' roll
Rock and roll (often written as rock & roll, rock 'n' roll, or rock 'n roll) is a genre of popular music that evolved in the United States during the late 1940s and early 1950s. It originated from African-American music such as jazz, rhythm an ...
guitarists such as
Willie Johnson,
Johnny Watson and
Link Wray. According to
AllMusic
AllMusic (previously known as All Music Guide and AMG) is an American online music database. It catalogs more than three million album entries and 30 million tracks, as well as information on musicians and bands. Initiated in 1991, the databas ...
's
Richie Unterberger
Richie Unterberger (born January 19, 1962) is an American author and journalist whose focus is popular music and travel writing.
Life and writing
Unterberger attended the University of Pennsylvania, where he wrote for the university newspaper '' ...
, the very first use of feedback on a commercial rock record is the introduction of the song "
I Feel Fine
"I Feel Fine" is a song by the English rock band the Beatles that was released in November 1964 as the A-side of their eighth single. It was written by John Lennon and credited to the Lennon–McCartney partnership. The recording includes one o ...
" by
the Beatles
The Beatles were an English Rock music, rock band, formed in Liverpool in 1960, that comprised John Lennon, Paul McCartney, George Harrison and Ringo Starr. They are regarded as the Cultural impact of the Beatles, most influential band of al ...
, recorded in 1964. Jay Hodgson agrees that it was the first chart-topper to showcase feedback distortion, created by
John Lennon
John Winston Ono Lennon (born John Winston Lennon; 9 October 19408 December 1980) was an English singer, songwriter, musician and peace activist who achieved worldwide fame as founder, co-songwriter, co-lead vocalist and rhythm guitarist of ...
leaning a semi-acoustic guitar against an amplifier.
The Who
The Who are an English rock band formed in London in 1964. Their classic lineup consisted of lead singer Roger Daltrey, guitarist and singer Pete Townshend, bass guitarist and singer John Entwistle, and drummer Keith Moon. They are considered ...
's 1965 hits "
Anyway, Anyhow, Anywhere
"Anyway, Anyhow, Anywhere" was the second single released by the English rock band the Who in 1965. It features call-and-response lyrics (especially common in Who lyrics at this time) and some of the first ever recorded guitar feedback. The song ...
" and "
My Generation
"My Generation" is a song by the English rock band the Who, which became a hit and one of their most recognizable songs. The song was named the 11th greatest song by ''Rolling Stone'' on its list of the 500 Greatest Songs of All Time. It becam ...
" featured feedback manipulation by
Pete Townshend
Peter Dennis Blandford Townshend (; born 19 May 1945) is an English musician. He is co-founder, leader, guitarist, second lead vocalist and principal songwriter of the Who, one of the most influential rock bands of the 1960s and 1970s.
Townsh ...
, with an extended solo in the former and the shaking of his guitar in front of the amplifier to create a throbbing noise in the latter.
Canned Heat
Canned Heat is an American band formed in Los Angeles, California, in 1965. The group is noted for its efforts to promote interest in blues music and its original artists and rock music. It was founded by two blues enthusiasts Alan Wilson and Bob ...
's "Fried Hockey Boogie" (off of their 1968 album ''
Boogie with Canned Heat
''Boogie with Canned Heat'' is the second studio album by American blues and rock band Canned Heat. Released in 1968, it contains mostly original material, unlike their debut album. It was the band's most commercially successful album, reaching ...
'') also featured guitar feedback produced by
Henry Vestine
Henry Charles Vestine (December 25, 1944 – October 20, 1997) a.k.a. "The Sunflower", was an American guitar player primarily known as a member of the band Canned Heat. He was with the group from its start in 1966 to July 1969. In later years ...
during his solo to create a highly amplified distorted boogie style of feedback. In 1963, the teenage
Brian May
Brian Harold May (born 19 July 1947) is an English guitarist, singer, songwriter, and astrophysicist, who achieved worldwide fame as the lead guitarist of the rock band Queen. May was a co-founder of Queen with lead singer Freddie Mercury and ...
and his father custom-built his signature guitar
Red Special
The Red Special is the electric guitar designed and built by Queen's guitarist Brian May and his father, Harold, when Brian was a teenager in the early 1960s. The Red Special is sometimes referred to as the Fireplace or the Old Lady by May and ...
, which was purposely designed to feed back.
Feedback was used extensively after 1965 by
the Monks
The Monks, referred to by the name monks on record sleeves, were an American garage rock band formed in Gelnhausen, West Germany in 1964. Assembled by five American GIs stationed in the country, the group grew tired of the traditional format ...
,
Jefferson Airplane
Jefferson Airplane was an American rock band based in San Francisco, California, that became one of the pioneering bands of psychedelic rock. Formed in 1965, the group defined the San Francisco Sound and was the first from the Bay Area to ac ...
,
the Velvet Underground
The Velvet Underground was an American rock band formed in New York City in 1964. The original line-up consisted of singer/guitarist Lou Reed, multi-instrumentalist John Cale, guitarist Sterling Morrison, and drummer Angus MacLise. MacLise ...
and the
Grateful Dead
The Grateful Dead was an American rock music, rock band formed in 1965 in Palo Alto, California. The band is known for its eclectic style, which fused elements of rock, Folk music, folk, country music, country, jazz, bluegrass music, bluegrass, ...
, who included in many of their live shows a segment named ''Feedback'', a several-minutes long feedback-driven improvisation. Feedback has since become a striking characteristic of rock music, as
electric guitar
An electric guitar is a guitar that requires external amplification in order to be heard at typical performance volumes, unlike a standard acoustic guitar (however combinations of the two - a semi-acoustic guitar and an electric acoustic gu ...
players such as
Jeff Beck
Geoffrey Arnold Beck (born 24 June 1944) is an English rock guitarist. He rose to prominence with the Yardbirds and after fronted the Jeff Beck Group and Beck, Bogert & Appice. In 1975, he switched to a mainly instrumental style, with a focus ...
, Pete Townshend,
Dave Davies
David Russell Gordon Davies (born 3 February 1947) is an English guitarist, singer and songwriter. He was the lead guitarist and backing vocalist for the English rock band the Kinks, which also featured his elder brother Ray Davies. He was in ...
,
Steve Marriott
Stephen Peter Marriott (30 January 1947 – 20 April 1991) was an English guitarist, singer and songwriter. He co-founded and played in the rock bands Small Faces and Humble Pie, in a career spanning over two decades. Marriott was inducted pos ...
and
Jimi Hendrix
James Marshall "Jimi" Hendrix (born Johnny Allen Hendrix; November 27, 1942September 18, 1970) was an American guitarist, singer and songwriter. Although his mainstream career spanned only four years, he is widely regarded as one of the most ...
deliberately induced feedback by holding their guitars close to the
amplifier's speaker. Jazz guitarist
Gábor Szabó
Gábor István Szabó (March 8, 1936 – February 26, 1982) was a Hungarian American guitarist whose style incorporated jazz, pop, rock, and Hungarian music.
Early years
Szabó was born in Budapest, Hungary. He began playing guitar at the age ...
was one of the earliest jazz musicians to use controlled feedback in his music, which is prominent on his live album ''
The Sorcerer
''The Sorcerer'' is a two-act comic opera, with a libretto by W. S. Gilbert and music by Arthur Sullivan. It was the British duo's third operatic collaboration. The plot of ''The Sorcerer'' is based on a Christmas story, ''An Elixir of Lo ...
'' (1967). Szabó's method included the use of a flat top acoustic guitar with a magnetic pickup.
Lou Reed
Lewis Allan Reed (March 2, 1942October 27, 2013) was an American musician, songwriter, and poet. He was the guitarist, singer, and principal songwriter for the rock band the Velvet Underground and had a solo career that spanned five decades. ...
created his album ''
Metal Machine Music
''Metal Machine Music'' (subtitled ''*The Amine β Ring'') is the fifth studio album by American rock musician Lou Reed. It was recorded on a three-speed Uher machine and was mastered/engineered by Bob Ludwig. It was released as a double album ...
'' (1975) entirely from loops of feedback played at various speeds. An example of feedback can be heard on Hendrix's performance of "Can You See Me?" at the
Monterey Pop Festival
The Monterey International Pop Festival was a three-day music festival held June 16 to 18, 1967, at the Monterey County Fairgrounds in Monterey, California. The festival is remembered for the first major American appearances by the Jimi Hendrix ...
. The entire guitar solo was created using amplifier feedback.
Introductions, transitions, and fade-outs
In addition to "I Feel Fine", feedback was used on the introduction to songs including
Jimi Hendrix
James Marshall "Jimi" Hendrix (born Johnny Allen Hendrix; November 27, 1942September 18, 1970) was an American guitarist, singer and songwriter. Although his mainstream career spanned only four years, he is widely regarded as one of the most ...
's "
Foxy Lady
"Foxy Lady" (or alternatively "Foxey Lady") is a song by the Jimi Hendrix Experience. It first appeared on their 1967 debut album ''Are You Experienced'' and was later issued as their third single in the U.S. with the alternate spelling. It is o ...
", the Beatles' "
It's All Too Much
"It's All Too Much" is a song by the English rock band the Beatles from their 1969 album '' Yellow Submarine''. Written by George Harrison in 1967, it conveys the ideological themes of that year's Summer of Love. The Beatles recorded the track ...
", Hendrix's "
Crosstown Traffic",
David Bowie
David Robert Jones (8 January 194710 January 2016), known professionally as David Bowie ( ), was an English singer-songwriter and actor. A leading figure in the music industry, he is regarded as one of the most influential musicians of the ...
's "
Little Wonder",
the Strokes
The Strokes are an American rock band from New York City. Formed in 1998, the band is composed of lead singer and songwriter Julian Casablancas, guitarists Nick Valensi and Albert Hammond Jr., bassist Nikolai Fraiture, and drummer Fabrizio More ...
's "New York City Cops",
Ben Folds Five's "
Fair
A fair (archaic: faire or fayre) is a gathering of people for a variety of entertainment or commercial activities. Fairs are typically temporary with scheduled times lasting from an afternoon to several weeks.
Types
Variations of fairs incl ...
",
Midnight Juggernauts
Midnight Juggernauts were an Australian band from Melbourne, composed of Andrew Szekeres, Vincent Vendetta (Vincent Heimann), and Daniel Stricker. The band has been described as anything from 'prog dance meets cosmic film scores', to 'slasher-fl ...
's "Road to Recovery",
Nirvana
( , , ; sa, निर्वाण} ''nirvāṇa'' ; Pali: ''nibbāna''; Prakrit: ''ṇivvāṇa''; literally, "blown out", as in an oil lampRichard Gombrich, ''Theravada Buddhism: A Social History from Ancient Benāres to Modern Colombo.' ...
's "Radio Friendly Unit Shifter",
the Jesus and Mary Chain
The Jesus and Mary Chain are a Scottish alternative rock band formed in East Kilbride in 1983. The band revolves around the songwriting partnership of brothers Jim and William Reid. After signing to independent label Creation Records, they rele ...
's "Tumbledown" and "
Catchfire
''Catchfire'' is a 1990 American romantic action thriller film directed by Dennis Hopper and starring Jodie Foster, Hopper, Fred Ward and Vincent Price, with cameo appearances by several notable actors, including Charlie Sheen, Joe Pesci, Cath ...
",
the Stone Roses
The Stone Roses were an English Rock music, rock band formed in Manchester in 1983. One of the pioneering groups of the Madchester movement in the late 1980s and early 1990s, the band's classic and most prominent lineup consisted of vocalist I ...
's "
Waterfall
A waterfall is a point in a river or stream where water flows over a vertical drop or a series of steep drops. Waterfalls also occur where meltwater drops over the edge of a tabular iceberg or ice shelf.
Waterfalls can be formed in several wa ...
",
Porno for Pyros
Porno for Pyros is an American alternative rock band formed in Los Angeles, California, United States in 1992, following the break-up of Jane's Addiction. The band currently consists of former Jane's Addiction members Perry Farrell (vocals) and ...
's "Tahitian Moon",
Tool
A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task. Although many animals use simple tools, only human beings, whose use of stone tools dates ba ...
's "
Stinkfist", and
the Cure
The Cure are an English Rock music, rock band formed in 1978 in Crawley, Crawley, West Sussex. Throughout numerous lineup changes since the band's formation, guitarist, lead vocalist, and songwriter Robert Smith (musician), Robert Smith has re ...
's "Prayer For Rain".
Examples of feedback combined with a quick volume swell used as a transition include
Weezer
Weezer is an American rock band formed in Los Angeles, California, in 1992. Since 2001, the band has consisted of Rivers Cuomo (vocals, guitar, keyboards), Patrick Wilson (drums, backing vocals), Scott Shriner (bass guitar, keyboards, backing ...
's "
My Name Is Jonas
"My Name Is Jonas" is a song by the American rock band Weezer. It is the first track on the band's self-titled 1994 debut album, also known as ''The Blue Album''. It was written by guitarist/vocalist Rivers Cuomo, drummer Patrick Wilson and gui ...
" and "
Say It Ain't So
"Say It Ain't So" is a song by the American rock band Weezer. It was released as the third and final single from the band's self-titled 1994 debut album.
Written by frontman Rivers Cuomo, the song came to be after he had all the music finishe ...
"; The Strokes' "
Reptilia
Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephalians ( ...
", "New York City Cops", and "
Juicebox";
Dream Theater
Dream Theater is an American progressive metal band formed in 1985 under the name Majesty by John Petrucci, John Myung and Mike Portnoy while they attended Berklee College of Music in Boston, Massachusetts. They subsequently dropped out of the ...
's "
As I Am
''As I Am'' is the third studio album by American singer and songwriter Alicia Keys. It was released on November 9, 2007 by J Records. Recording sessions for the album took place at various recording studios from 2005 until 2007. Production was h ...
"; as well as numerous tracks by
Meshuggah
Meshuggah () is a Swedish extreme metal band formed in Umeå in 1985. Originally, the band's name was Metallien. The band's current lineup consists of lead vocalist Jens Kidman, guitarists Fredrik Thordendal and Mårten Hagström, drummer To ...
and Tool.
Cacophonous feedback
fade-out
In audio engineering, a fade is a gradual increase or decrease in the level of an audio signal. The term can also be used for film cinematography or theatre lighting in much the same way (see fade (filmmaking) and fade (lighting)).
A recor ...
s ending a song are most often used to generate rather than relieve tension, often cross-faded too after a thematic and musical release. Examples include
Modwheelmood
Modwheelmood (also typeset as ModWheelMood or modwheelmood and abbreviated as MWM) is an American Electronic-Alternative band from Los Angeles, California formed by Alessandro Cortini (who is also part of the Nine Inch Nails live lineup from 20 ...
's remix of Nine Inch Nail's "The Great Destroyer"; and the Jesus and Mary Chain's "Teenage Lust", "Tumbledown", "
Catchfire
''Catchfire'' is a 1990 American romantic action thriller film directed by Dennis Hopper and starring Jodie Foster, Hopper, Fred Ward and Vincent Price, with cameo appearances by several notable actors, including Charlie Sheen, Joe Pesci, Cath ...
", "Sundown", and "Frequency".
Examples in modern classical music
Though closed circuit feedback was a prominent feature in many early experimental
electronic music
Electronic music is a genre of music that employs electronic musical instruments, digital instruments, or circuitry-based music technology in its creation. It includes both music made using electronic and electromechanical means ( electroac ...
compositions, it was contemporary American composer
Robert Ashley
Robert Reynolds Ashley (March 28, 1930 – March 3, 2014) was an American composer, who was best known for his television operas and other theatrical works, many of which incorporate electronics and extended techniques. His works often involve i ...
who first used acoustic feedback as sound material in his work ''The Wolfman'' (1964).
Steve Reich
Stephen Michael Reich ( ; born October 3, 1936) is an American composer known for his contribution to the development of minimal music in the mid to late 1960s. Reich's work is marked by its use of repetitive figures, slow harmonic rhythm, a ...
makes extensive use of audio feedback in his work ''
Pendulum Music
''Pendulum Music'' (For Microphones, Amplifiers Speakers and Performers) Reich, S. (1974). "''Pendulum Music''". In '' Writings About Music'' (pp. 12–13). The Press of the Nova Scotia College of Art and Design (Co-published by: New York Univ ...
'' (1968) by swinging a series of microphones back and forth in front of their corresponding amplifiers.
Hugh Davies and
Alvin Lucier both use feedback in their works. More recent examples can be found in the work of for example Lara Stanic,
Paul Craenen,
Anne Wellmer,
Adam Basanta, Lesley Flanigan, Ronald Boersen and Erfan Abdi.
Pitched feedback
Pitched melodies may be created entirely from feedback through changing the angle between a guitar and amplifier after establishing a feedback loop. Examples include
Tool
A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task. Although many animals use simple tools, only human beings, whose use of stone tools dates ba ...
's "
Jambi",
Robert Fripp
Robert Fripp (born 16 May 1946) is a British musician, songwriter, record producer, and author, best known as the guitarist, founder and longest-lasting member of the progressive rock band King Crimson. He has worked extensively as a session ...
's guitar on
David Bowie
David Robert Jones (8 January 194710 January 2016), known professionally as David Bowie ( ), was an English singer-songwriter and actor. A leading figure in the music industry, he is regarded as one of the most influential musicians of the ...
's "
Heroes
Heroes or Héroes may refer to:
* Hero, one who displays courage and self-sacrifice for the greater good
Film
* ''Heroes'' (1977 film), an American drama
* ''Heroes'' (2008 film), an Indian Hindi film
Gaming
* ''Heroes of Might and Magic'' ...
" (album version), and
Jimi Hendrix
James Marshall "Jimi" Hendrix (born Johnny Allen Hendrix; November 27, 1942September 18, 1970) was an American guitarist, singer and songwriter. Although his mainstream career spanned only four years, he is widely regarded as one of the most ...
's "
Third Stone from the Sun
"Third Stone from the Sun" (or "3rd Stone from the Sun") is a mostly instrumental composition by American musician Jimi Hendrix. It incorporates several musical approaches, including jazz and psychedelic rock, with brief spoken passages. The ti ...
" and his live performance of "
Wild Thing" at the
Monterey Pop Festival
The Monterey International Pop Festival was a three-day music festival held June 16 to 18, 1967, at the Monterey County Fairgrounds in Monterey, California. The festival is remembered for the first major American appearances by the Jimi Hendrix ...
.
Regarding Fripp's work on "Heroes":
Contemporary uses
Audio feedback became a signature feature of many underground rock bands during the 1980s. American
noise-rock
Noise rock (sometimes called noise punk) is a noise-oriented style of experimental rock that spun off from punk rock in the 1980s. Drawing on movements such as minimalism, industrial music, and New York hardcore, artists indulge in extreme l ...
ers
Sonic Youth
Sonic Youth was an American rock band based in New York City, formed in 1981. Founding members Thurston Moore (guitar, vocals), Kim Gordon (bass, vocals, guitar) and Lee Ranaldo (guitar, vocals) remained together for the entire history of the b ...
melded the rock-feedback tradition with a compositional/classical approach (notably covering Reich's "Pendulum Music"), and guitarist/producer
Steve Albini
Steve Albini (pronounced ; born July 22, 1962) is an American musician, record producer, audio engineer and music journalist. He was a member of Big Black, Rapeman and Flour, and is a member of Shellac. He is the founder, owner and principal en ...
's group
Big Black also worked controlled feedback into the makeup of their songs. With the
alternative rock
Alternative rock, or alt-rock, is a category of rock music that emerged from the independent music underground of the 1970s and became widely popular in the 1990s. "Alternative" refers to the genre's distinction from Popular culture, mainstre ...
movement of the 1990s, feedback again saw a surge in popular usage by suddenly mainstream acts like
Nirvana
( , , ; sa, निर्वाण} ''nirvāṇa'' ; Pali: ''nibbāna''; Prakrit: ''ṇivvāṇa''; literally, "blown out", as in an oil lampRichard Gombrich, ''Theravada Buddhism: A Social History from Ancient Benāres to Modern Colombo.' ...
, the
Red Hot Chili Peppers
Red Hot Chili Peppers are an American rock music, rock band formed in Los Angeles in 1983, comprising vocalist Anthony Kiedis, bassist Flea (musician), Flea, drummer Chad Smith, and guitarist John Frusciante. Their music incorporates element ...
,
Rage Against the Machine
Rage Against the Machine (often abbreviated as RATM or shortened to simply Rage) is an American rock band from Los Angeles, California. Formed in 1991, the group consists of vocalist Zack de la Rocha, bassist and backing vocalist Tim Commerfor ...
and
the Smashing Pumpkins
The Smashing Pumpkins (also referred to as simply Smashing Pumpkins) are an American alternative rock band from Chicago. Formed in 1988 by frontman and guitarist Billy Corgan, bassist D'arcy Wretzky, guitarist James Iha and drummer Jimmy Chamb ...
. The use of the "no-input-mixer" method for sound generation by feeding a mixing console back into itself has been adopted in experimental electronic and noise music by practitioners such as
Toshimaru Nakamura
Toshimaru Nakamura is a Japanese musician, active in free improvisation and Japanese Onkyokei, onkyo.
He began his career playing rock and roll guitar, but gradually explored other types of music, even abandoning guitar, and started working on ...
.
Devices
![Thomas Organ Cry Baby & Boss DF-2 Super Feedbacker & Distortion](https://upload.wikimedia.org/wikipedia/commons/4/40/Thomas_Organ_Cry_Baby_%26_Boss_DF-2_Super_Feedbacker_%26_Distortion.jpg)
The principle of feedback is used in many guitar sustain devices. Examples include handheld devices like the
EBow
The EBow, short for electronic bow or energy bow, is an electronic device used for playing string instruments, most often the electric guitar. It is manufactured by Heet Sound Products, of Los Angeles, California. It was invented by Greg Heet i ...
, built-in guitar pickups that increase the instrument's sonic sustain, string drivers mounted on a stand such as the
Guitar Resonator, and sonic transducers mounted on the head of a guitar. Intended closed-circuit feedback can also be created by an
effects unit
An effects unit or effects pedal is an electronic device that alters the sound of a musical instrument or other audio source through audio signal processing.
Common effects include distortion/overdrive, often used with electric guitar in el ...
, such as a delay pedal or effect fed back into a
mixing console
A mixing console or mixing desk is an electronic device for mixing audio signals, used in sound recording and reproduction and sound reinforcement systems. Inputs to the console include microphones, signals from electric or electronic inst ...
. The feedback can be controlled by using the fader to determine a volume level. The Boss DF-2 Super Feedbacker and Distortion pedal is an electronic
effect unit
An effects unit or effects pedal is an electronic device that alters the sound of a musical instrument or other audio source through audio signal processing.
Common effects include distortion/overdrive, often used with electric guitar in ele ...
that helps electric guitarists to create feedback effects. The
halldorophone
The halldorophone (; also known as the dorophone, and dórófónn in Icelandic) is a cello-like electronic instrument created by artist and designer Halldór Úlfarsson. The halldorophone is designed specifically to feedback the strings, making ...
is an electro-acoustic string instrument specifically made to work with string based feedback.
[http://www.nime.org/proceedings/2018/nime2018_paper0058.pdf ]
See also
*
Circuit bending
*
Comb filter
In signal processing, a comb filter is a filter implemented by adding a delayed version of a signal to itself, causing constructive and destructive interference. The frequency response of a comb filter consists of a series of regularly spaced no ...
*
Distortion (music)
Distortion and overdrive are forms of audio signal processing used to alter the sound of amplified electric musical instruments, usually by increasing their gain, producing a "fuzzy", "growling", or "gritty" tone. Distortion is most commonly ...
*
Echo cancellation
Echo suppression and echo cancellation are methods used in telephony to improve voice quality by preventing echo from being created or removing it after it is already present. In addition to improving subjective audio quality, echo suppression ...
*
Feedback suppressor
A feedback suppressor is an audio signal processing device which is used in the signal path in a live sound reinforcement system to prevent or suppress audio feedback.
Digital feedback reduction is the application of digital techniques to sound re ...
*
Video feedback
Video feedback is the process that starts and continues when a video camera is pointed at its own playback video monitor. The loop delay from camera to display back to camera is at least one video frame time, due to the input and output scanni ...
References
External links
Sound Improving Means and Method, U.S. Patent No. 3,624,298 early pioneer in studying feedback.
Charles Paul Boner* {{cite web, title=Understanding Acoustic Feedback & Suppressors, publisher=
Rane, url=https://www.ranecommercial.com/legacy/note158.html, work=RaneNote, number=158, last=Troxel, first=Dana, date=October 2005
Audio effects
Audio electronics
Rock music
Guitar performance techniques
Feedback
he:היזון חוזר (מוזיקה)