question: When we hear our voices in real life when we speak, why does it sound different to what we hear on recordings?
comment: When you hear yourself when you’re speaking, it’s vibrating more through your jaw than the air, which makes a different noise since it’s not hitting your eardrums in the same place. However, microphones and recordings are made to sound exactly like soundwaves in the air, which sound different.
passages: Section::::Overview.
  
  Bone conduction is one reason why a person's voice sounds different to them when it is recorded and played back. Because the skull conducts lower frequencies better than air, people perceive their own voices to be lower and fuller than others do, and a recording of one's own voice frequently sounds higher than one expects.
   BULLET::::- Poughkeepsie "Sunday Courier" (May 3, 1931): "If a certain crusading congressman could have seen last night's production he would have probably branded the whole company as dangerous, if not Red agitators."
   The conclusion to make from both the identification and the discrimination test is that listeners will have different sensitivity to the same relative increase in VOT depending on whether or not the boundary between categories was crossed. Similar perceptual adjustment is attested for other acoustic cues as well.
  
  Section::::Basics.:Top-down influences.
   Artifacts created during attempts to boost the clarity of an existing recording might explain some EVP. Methods include re-sampling, frequency isolation, and noise reduction or enhancement, which can cause recordings to take on qualities significantly different from those that were present in the original recording.
  
  The very first EVP recordings may have originated from the use of tape recording equipment with poorly aligned erasure and recording heads, resulting in the incomplete erasure of previous audio recordings on the tape. This could allow a small percentage of previous content to be superimposed or mixed into a new 'silent' recording.
   One of the fundamental problems in the study of speech is how to deal with noise. This is shown by the difficulty in recognizing human speech that computer recognition systems have. While they can do well at recognizing speech if trained on a specific speaker's voice and under quiet conditions, these systems often do poorly in more realistic listening situations where humans would understand speech without relative difficulty. To emulate processing patterns that would be held in the brain under normal conditions, prior knowledge is a key neural factor, since a robust learning history may to an extent override the extreme masking effects involved in the complete absence of continuous speech signals.
   BULLET::::- Carrie McCrossen: John, ensemble
  
  BULLET::::- Tonya Canada: Doscher, Harriet
  
  BULLET::::- Rebecca Servon: Rose, ensemble
  
  BULLET::::- Mick Hilgers: Drdla, ensemble
  
  BULLET::::- Patricia Drozda: Purcell, ensemble
  
  BULLET::::- Sarah Elizondo: Hilda, ensemble
  
  Section::::Production details.:Theatrical runs.:Details of 2010 theatrical run.:Orchestra.
  
  BULLET::::- Aaron Dai: piano
  
  BULLET::::- Brian Mark: clarinet
  
  BULLET::::- Samuel C. Nedel: bass
  
  Section::::Production details.:Reviews.
  
  Section::::Production details.:Reviews.:1930s Reviews.
  
  Flanagan's changes (cited under "Differences," above) are reflected in critical responses in the press:
   One example of visual capture is known as the "ventriloquism effect," which refers to the perception of speech sounds as coming from a direction other than their true direction, due to the influence of visual stimuli from an apparent speaker. Thus, when the ventriloquism illusion occurs, the speaker's voice is visually captured at the location of the dummy's moving mouth (rather than the speaker's carefully unmoving mouth).
   Another unique challenge is a relatively low signal-to-noise ratio (SNR) in the recorded data. A SNR represents the amount of meaningful signals found in a data set, compared to the amount of arbitrary or useless signals present in the same set. Artifacts present in EEG data are just one of many significant sources of noise.
  
  To further complicate matters, the relative placement of EEG electrodes will vary amongst subjects. This is because the anatomical details of people's heads will differ; therefore, the signals recorded will vary in each subject, regardless of individuals-specific imagined speech characteristics.
  
  Section::::Limitations for practical communication.
   BULLET::::- "Show Business Weekly" (June 8, 2010): "This brisk production, under Ralph Lewis and Barry Rowell’s direction, brings Chambers’s story to life with live music and projections of Depression-era footage by Matthew Tennie that smooth the transition between scenes. Deb O’s period costumes expertly evoke the era and add depth to Nikolay Levin’s minimal set, which uses platforms to make the best of its site-specific location. The cast consistently performs as a well-integrated ensemble, with all the actors playing extras in addition to their main roles. Their energetic performances have that rousing quality, which is so essential to the genre."
   BULLET::::- "New York Theatre" (June 5, 2010): "The play itself feels dated and stiff, very much an artifact of a period when American dramatists were only starting to find their native voice and learn to tell stories of our country with depth and texture. But the history it recounts—for it is based, we are told, on actual events—is eminently worth remembering. And it's easy to understand why the good people at Peculiar Works Project have chosen to bring it to the stage at this particular moment, for the parallels between then and now are pretty clear."
   Section::::Production.
  
  In an interview with Mina Hochberg at AMCTV.com, Patrick Gilmore spoke about from whom he modeled his character, Tom Drexler: "The model they gave me was Mark Cuban. I don't think it's a direct impersonation, but it's definitely somewhere to start: a self-made millionaire, young, has the world at his hands and is able to manipulate the environment and the world around him. That's clearly something that Drexler has an ability to do."
  
  Section::::Reception.
   The effect reverses in a reverberation room, which echoes real life more so than the typical quiet rooms used for experimentation. This allows for echoes of the spoken phonemes to act as the replacement noise for the missing phonemes. The additional produced white noise that replaces the phoneme adds its own echo and causes listeners to not perform as well.
  
  Section::::Factors.:Rate.
   Every location has a distinct presence created by the position of the microphone in relation to the space boundaries. A microphone placed in two different parts of the same room will record two distinct presences. This is because of the unique spatial relationship between the microphone and boundaries such as walls, ceilings, and floors, and other objects in a room.
   Audio can be encoded at different sampling rates (i.e. samples per second – the most common being: 8, 16, 32, 44.1, 48, and 96 kHz), and different bits per sample (the most common being: 8-bits, 16-bits, 24-bits or 32-bits). Speech recognition engines work best if the acoustic model they use was trained with speech audio which was recorded at the same sampling rate/bits per sample as the speech being recognized.
  
  Section::::Telephony-based speech recognition.
   BULLET::::3. The human head imprints frequency-dependent distortions of phase and amplitude on sounds as they reach the eardrums. The frequency-dependent level differences as well as these distortions vary with the direction of the sound source. This is caused by the geometry and sound-transmitting characteristics of the sinus, throat cavities, eustachian tubes, inner ear, external ears and other tissues of the head and upper body. [See: Head Related Transfer Function, “HRTF”]
   Section::::Media.:Binaural recording.
  
  Some ASMR video creators use binaural recording techniques to simulate the acoustics of a three-dimensional environment, reported to elicit in viewers and listeners the experience of being in proximity to actor and vocalist. Binaural recordings are usually made using two microphones, just like stereo recordings. However, in binaural recordings, the two microphones tend to be more specially designed to mimic ears on humans. In many cases, microphones are separated the same distance as ears are on humans, and microphones are surrounded by ear-shaped cups to get similar reverb as human ears.
   "Legion", a 1983 novel by William Peter Blatty, contains a subplot where Dr. Vincent Amfortas, a terminally ill neurologist, leaves a "to-be-opened-upon-my-death" letter for Father Dyer detailing his accounts of contact with the dead, including the doctor's recently deceased wife, Ann, through EVP recordings. Amfortas' character and the EVP subplot do not appear in the film version of the novel, "The Exorcist III", although in Kinderman's dream dead people are seen trying to communicate with the living by radio.
   BULLET::::- David Castaneda: lighting
  
  BULLET::::- Nikolay Levin: sets
  
  BULLET::::- Deb O: costumes
  
  BULLET::::- Gwen Orel: dramaturg
  
  BULLET::::- Matthew Tennie: projection
  
  BULLET::::- Seth Bedford: music
  
  BULLET::::- Peculiar Works Project: archival video
  
  BULLET::::- Ryan Holsopple: sound
  
  BULLET::::- Marte Johanne Ekhoougen: props
  
  BULLET::::- Cathy Carlton: production associate/swing actor
  
  Set and light crew included: Christoper Hurt, Janet Bryant, Dror Shnayer, Diana Byrne, Tricia Byrne, and Skip LaPlante.
  
  Section::::Production details.:Theatrical runs.:Details of 2010 theatrical run.:Cast (in order of speaking).
  
  BULLET::::- Ben Kopit: Frank, Bill
  
  BULLET::::- Derek Jamison: Davis, ensemble
  
  BULLET::::- Catherine Porter: Ann, ensemble
  
  BULLET::::- Christopher Hurt: Wardell, ensemble
  
  BULLET::::- Ken Glickfield: Sam, Congressman Bagehot
   BULLET::::- "Theater Online" (undated): "PWP’s production of Voices in the vacant storefront at 2 Great Jones Street in Noho fits perfectly with the company’s long-standing mission to “wake up” non-theater sites for theatrical performance."
  
  Section::::Production details.:Characters.
  
  BULLET::::- Jim Wardell, farmer
  
  BULLET::::- Ann Wardell, his wife
  
  BULLET::::- John Wardell, 14-year-old son
  
  BULLET::::- Sam Wardell, 12-year-old son
  
  BULLET::::- Frank Francis, a young farmer
  
  BULLET::::- Hilda Francis, his wife
  
  BULLET::::- Mort Davis, an old farmer
  
  BULLET::::- Dirdla, a Russian farmer
  
  BULLET::::- Rose, his 18-year-old daughter
  
  BULLET::::- Ms. Smythe, radio announcer
  
  BULLET::::- Mr. Wordsworth, radio commentator
  
  BULLET::::- Purcell, a rich local businessman
   BULLET::::- "The New York Times" (May 10, 1931): "a searing, biting, smashing piece of propaganda"
  
  BULLET::::- "Theatre Guild Magazine" (July 1931): "frankly propagandist play... (that) deeply moved its audiences."
  
  BULLET::::- "Theatre Arts Monthly" (undated, probably 1931): "a good play, of important native material, well characterized, handling experimental technical material skillfully, worth any theatre's attention--amateur or professional."
  
  BULLET::::- "Workers' Theatre" (January 1932): "Flanagan and Clifford mutilated the class line of the story and adapted it into a play form with a clear liberal ideology."
  
  Section::::Production details.:Reviews.:2010s Reviews.
  
  Change in times leads many reviewers to overlook key elements in story and style:
   Latency in digital audio equipment is most noticeable when a singer's voice is transmitted through their microphone, through digital audio mixing, processing and routing paths, then sent to their own ears via in ear monitors or headphones. In this case, the singer's vocal sound is conducted to their own ear through the bones of the head, then through the digital pathway to their ears a few milliseconds later. In one study listeners found latency greater than 15ms to be noticeable.
   BULLET::::- Kim Hae-sook as Eo Choon-shim, Hye-sung's mother
  
  BULLET::::- Kim Byung-ok as Hwang Dal-joong, Joon-gook's cellmate
  
  BULLET::::- Jung Dong-hwan as Judge Seo Dae-seok, Do-yeon's father
  
  BULLET::::- Jang Hee-soo as Do-yeon's mother
  
  BULLET::::- Jo Deok-hyeon as Park Joo-hyeok, Soo-ha's father
  
  BULLET::::- Kim Soo-yeon as Moon Dong-hee, Sung-bin's classmate who is an upcoming entertainer
  
  BULLET::::- Jang Hee-woong as Prosecutor Jo, nicknamed "Mr. Grass-like Hair"
  
  Section::::Cast.:Special appearances.
  
  BULLET::::- So Yi-hyun as Joon-gook's lawyer (cameo, ep 1, 12)
  
  BULLET::::- Kim Sung-kyun as detective (cameo, ep 1)
  
  BULLET::::- Jeon Soo-kyung as dental pad lady (cameo, ep 1)
   Section::::Performance evaluation.
  
  To evaluate a VAD, its output using test recordings is compared with those of an “ideal” VAD – created by hand-annotating the presence/absence of voice in the recordings. The performance of a VAD is commonly evaluated on the basis of the following four parameters:
  
  BULLET::::- FEC (Front End Clipping): clipping introduced in passing from noise to speech activity;
  
  BULLET::::- MSC (Mid Speech Clipping): clipping due to speech misclassified as noise;
  
  BULLET::::- OVER: noise interpreted as speech due to the VAD flag remaining active in passing from speech activity to noise;
   "Auditory pareidolia" is a situation created when the brain incorrectly interprets random patterns as being familiar patterns. In the case of EVP it could result in an observer interpreting random noise on an audio recording as being the familiar sound of a human voice. The propensity for an apparent voice heard in white noise recordings to be in a language understood well by those researching it, rather than in an unfamiliar language, has been cited as evidence of this, and a broad class of phenomena referred to by author Joe Banks as "Rorschach Audio" has been described as a global explanation for all manifestations of EVP.
   Section::::Basics.:Perceptual constancy and normalization.
  