4 stars based on
Binaural recording is a method of recording sound that uses two microphonesarranged 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 recording ", wherein a mannequin head is outfitted with a microphone in each ear. Binaural recording is intended for replay using headphones and will not translate properly over stereo speakers. This idea of binaural audio three dimensional or "internal" form of sound has also translated into useful advancement of technology in many things such as stethoscopes creating "in-head" acoustics and IMAX movies being able to create a three dimensional acoustic experience.
The term "binaural" has frequently been confused as a synonym for the word " stereo ", and this is partially due to a large amount of misuse in the mids binaural audio the recording industryas a marketing buzzword. Conventional stereo recordings do not factor in natural ear spacing or " binaural audio shadow " of the head and ears, since these things happen naturally as a person listens, generating their binaural audio ITDs interaural time differences and ILDs interaural level differences.
Because loudspeaker-crosstalk of conventional stereo interferes with binaural reproduction, either headphones are required, or crosstalk cancellation of signals intended for loudspeakers such as Ambiophonics is required.
For listening using conventional speaker-stereo, or mp3 playersa pinna -less dummy head may be preferable for quasi-binaural recording, such as the sphere microphone or Ambiophone.
As a general rule, for true binaural results, an audio recording and reproduction system chain, from microphone to listener's brain, should contain one and only one set of pinnae preferably the listener's own and one head-shadow. This method will not create a real binaural recording.
The distance and placement roughly approximates the position of an average human's ear canalsbut that is not all that is needed. More elaborate techniques exist in pre-packaged forms.
A typical binaural recording unit has binaural audio high-fidelity microphones mounted in a dummy head, inset in ear-shaped molds binaural audio fully binaural audio all of the audio frequency adjustments known as head-related transfer functions HRTFs in binaural audio psychoacoustic research community that happen naturally as sound wraps around the human head and is "shaped" by the form of the outer and inner ear. A simplified version of binaural recordings can be achieved using microphones with a binaural audio element, like the Jecklin Disk.
Not all cues required for exact localization binaural audio the sound sources can be preserved this way, but it also works well for loudspeaker reproduction. In the late s, Aiwa and Sony offered headphones with a pair of microphones mounted on the headband around two inches above the ears. These allowed binaural audio recordings to binaural audio made. Miniature binaural "in-ear" or "near-ear" microphones can be linked to a portable Digital Audio Tape DAT or MiniDisc recorder, bypassing the need for a dummy head by using the recordist's own head.
The first clip-in binaural audio microphones using the recordist's own head were offered by Sennheiser in The first clip-on binaural microphones using the recordist's own head were offered by Core Sound LLC in Binaural audio first completely "in-ear" binaural microphones using the recordist's own head were offered by Sound Professionals in The technique of binaural audio re-recording is simple, but has not been well established. It follows the same principles of Worldizing,  a technique used by film sound designers in which sound is played over loud speaker in a real world location and then re-recorded, taking along all the aspects and characteristics of the real world environment with it.
Using space to manipulate a sound and then being re-recorded is also nothing new as it is something that has been done through the use of echo-chambers in recording studios for many years. Inan echo-chamber was famously used by Irving Townsend during the post production process of Miles Davis's album 'Kind of Blue'. At 30th Street, a line was run from the mixing console down into a low-ceilinged, concrete basement room - about twelve by fifteen feet in size - where we set up a speaker and a good omnidirectional microphone.
In binaural re-recording, a binaural microphone is used to record content being played over a multi-channel speaker set-up. The binaural head, or microphone, is therefore theoretically making a recording binaural audio how humans will hear multi-channel content.
The soundtrack to a film for example will be recorded by the binaural microphone with all the environmental cues of the given location, as well as reverberations, including those commonly created by our own torso assuming a HATS  model is used. There is binaural audio common issue of binaural audio simply not being able to understand binaural recordings, and in most cases being unable to hear a sense of externalisation.
However this issue is common among all binaural recording, and isn't a localised issue to re-recording. Although it is worth pointing out that this is the case with all methods of improving spatial awareness in soundtracks. Once recorded, the binaural effect can be reproduced using headphones. It does not work with mono playback; nor does binaural audio work while using loudspeaker units, as the acoustics of this arrangement distort the channel separation via natural crosstalk an approximation can be obtained if binaural audio listening environment is carefully designed by employing expensive crosstalk cancellation equipment.
Any set of headphones that provides good right and left channel isolation is sufficient to hear the immersive effects of the recording. Several high-end head set manufacturers have binaural audio some units specifically for the playback of binaural. It is also found that even normal headphones suffer from poor externalization, especially if the headphone completely blocks the ear from outside. Binaural audio better design for externalization found in experiments is the open-ear one, where the drivers are binaural audio in front of the pinnae with the ear canal connected binaural audio the air.
The hypothesis is that when the ear canal is completely blocked, the radiation impedance seen from the eardrum to the outside binaural audio been altered, which negatively affects externalization. There are some complications with the playback of binaural recordings through headphones. Binaural audio sound that is picked up by a microphone placed in or at the entrance of the ear channel has a binaural audio spectrum that is very different from the one that would be picked up by a free-standing microphone.
The diffuse-field head-transfer function HRTFthat is, the frequency response at the ear drum averaged for sounds coming from all possible directions, is quite grotesque, with peaks and dips exceeding 10 dB. At the start of each variation the listener would binaural audio a series of test signals allowing for a choice of which version gives the listener the best spatial experience.
The release of Private Peaceful had an accompanying survey which all listeners were asked to complete. It asked questions about the success that the binaural reproduction had with the listeners and which version the listener thought was most successful. Francis Rumsey states in the article 'Whose head is it anyway? The HRTFs used for Private Peaceful  were binaural audio by measuring impulse responses in a reverberant room, done so to capture a sense of space, but is not very external and there are obvious timbral issues as pointed out by Pike.
This explains that there are ways of reducing the effects of timbral issues on audio that has been processed with HRTF data, but this does mean further Binaural audio manipulation of the audio. If this route is to be further explored, researchers will have to be happy with the fact that the audio is being manipulated in great amounts to achieve a greater sense of spacial awareness, and that this further manipulation will cause irreversible changes to the audio, something content creators may not be happy with.
Consideration will have to be taken into how much manipulation is appropriate and to what extent, if any, will this affect the end users experience. When recording a series of HRTF data, only a limited amount of measurements can be taken for distribution, and the end-users will have to find the best binaural audio for themselves. Of course the best HRTF data for any individuals will be the information that would be binaural audio from their own pinna, not something that content creators for mobile applications are currently taking part in.
Because of this, timbral issues may be unavoidable while using non-personal HRTF data, or attempting to distribute any audio that has already been affected by spatial manipulation. It may be that the most feasible route to improving spatial awareness in audio is to explore the possibilities of head tracking or other methods of collecting HRTF data at the user-end.
The headphones used by consumers will inevitably make an impact on the end results. An issue surrounding headphone binaural audio is the wide range in quality of consumer level headphones. Many mp3 players and tablets are traditionally supplied with low budget earphones and these can cause problems for spatially enhanced audio. Ideal listening conditions will most likely be experienced with headphones designed and calibrated to give an as binaural audio frequency response as possible in order to reduce colouration of the audio the user is listening to.
In most circumstances this has not seemed enough of a problem for end-users to make an investment into headphones that will allow them to hear audio exactly how the creator of the content intended, and will instead continue to use bundled headphones, or in some cases make investments into headphones endorsed and branded by certain artists.
The point raised by DR Mason in this interview is that even if a successful reproduction of audio in a more realistic 3D space is achieved, the effect could be damaged by the end users choice of binaural audio. Cheaper headphones, and indeed more expensive headphones with EQ colouration, will have an influence on how the audio is heard by the end user. Having headphones that add colouration to the audio heard will undoubtedly make disruptive changes.
This can disrupt any chances of experiencing an improved spatial soundtrack. The Neumann KU is a dummy head microphone used to record in binaural stereo. Torso reflections have been seen to be a considerable contributor to creating a successful binaural recording. The 3Dio range is binaural audio cheaper than the Neumann KU for example and therefore used more on a consumer to prosumer level. The 3Dio relies entirely in the use on pinna moulds to achieve a binaural effect from the stereo recording.
An in-ear wearable stereo microphone binaural audio like earphones, placed inside the human pinna. This microphone uses the binaural audio pinna to create the binaural effect.
The specific shapes and sizes of a binaural recording device "affect the behaviour - such as absorption, transmission, reflection, interference - of acoustic waves". The history of binaural recording goes back to The signal was sent binaural audio subscribers through the telephone system, and required that they wear a special head set, which had a tiny speaker for each ear.
The novelty wore off, and there wasn't significant interest in the technology until around forty years later when a Connecticut radio station began to broadcast binaural shows. Stereo radio had not yet been implemented, so the station actually broadcast the left channel on one frequency binaural audio the right channel on a second. Listeners would then have to own two radios, and plug the right and left ear pieces of their head sets into each radio. Naturally, the expense of owning two radios was, at the time, too much for a broad audience, and again binaural faded into obscurity.
InLou Reed released binaural audio first commercially produced binaural pop record, Street Hasslea combination of live and studio recordings. Binaural stayed in the background due to binaural audio expensive, specialized equipment required for quality recordings, and the requirement of headphones for proper reproduction. Particularly in pre- Walkman days, most consumers considered headphones an inconvenience, and were only binaural audio in recordings that could be listened to on a home stereo system or in automobiles.
Lastly, the types of things that can be recorded do not have a typically high market value. Recordings that are done in studios would have little to benefit binaural audio using a binaural set up, beyond natural cross-feed, as the spatial quality of the studio would not be very dynamic and interesting.
Recordings that are of interest are live orchestral performances, and ambient "environmental" recordings of city sounds, nature, and other such subject matters. A small grassroots movement of people building their own recording sets and swapping them on the Internet has joined binaural audio very few CDs available for purchase.
The online Binaural audio community is another movement of late which has widely employed binaural recordings. In David Cittadinialong with Andrew Hills, used binaural recording techniques and technologies on the Australian short film The Blind Passenger. On 29 August and 31 August they recorded The Metropolitan Orchestra using binaural recording techniques, the first recording of an orchestra in Australia using binaural recording techniques.
In Ninja Theory used binaural recording techniques for the video game Hellblade: This was done to immerse the player in the mindset of the player character, Senua, who is affected by psychosis and hears multiple voices in her head.
From Wikipedia, the free encyclopedia. This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.
December Learn how and when to remove this template message. Binaural recording of speech and paper crumpling. The desired effect can be achieved only with stereo headphones. This section does not cite any sources.
Please help improve this section by adding citations binaural audio reliable sources. September Learn how and when to remove this template message. Kind of Blue, The Making of a masterpiece.