Editing Binaural recording

{{Short description|Method of recording sound}}
{{Use Oxford spelling|date=February 2025}}
{{Use dmy dates|date=February 2025}}
{{More citations needed|date=December 2014}}
[[File:Georg Neumann Ku 100 Dummy Head.jpg|thumb|Neumann KU 100 microphone used to record binaural sound]]

'''Binaural recording''' is a method of [[Sound recording and reproduction|recording]] [[Sound recording|sound]] that uses two [[microphone]]s, arranged with the intent to create a [[Three-dimensional space|3D]] [[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 fitted 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 a 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 "[[Stereophonic sound|stereo]]", due in part to systematic use in the mid-1950s by the [[recording industry]], as a marketing [[buzzword]]. Conventional stereo recordings do not factor in natural ear spacing or "[[head shadow]]" of the head and ears, since these things happen naturally as a person listens, generating [[interaural time difference]]s (ITDs) and interaural level differences (ILDs) specific to their listening position. 

==History==
The history of binaural recording goes back to 1881.<ref name="Mattana 2017" /> The first binaural unit, the [[théâtrophone]], was invented by [[Clément Ader]].<ref name="Mattana 2017" /> It consisted of an array of spaced pairs of carbon pencil microphones installed along the front edge of the [[Palais Garnier|Opera Garnier]]. The signal was sent to subscribers through the [[telephone]] system, and required that they hold a headset up to each ear.

[[File:3D-stereo effect.png|thumb|upright|The key constituents that cause the 3D stereo effect: timing, loudness and [[timbre]]. Sound coming from the left arrives first to the left ear and microseconds later to the right ear. Head muffles the sound making the sound louder to the left ear than to the right ear. The head and other parts of the body deflect the sound thus changing the sound's frequency spectrum along its way from the left side to the right side. The human brain interprets these differences and automatically causes a sensation of a certain location for the sound to the listening person.<ref>{{Cite book |last=Rumsey |first=Francis |title=Spatial Audio |publisher=Focal Press |date=2001 |isbn=0-240-51623-0 |pages=62–64 }}</ref>]]

In the early 1930's, several binaural heads were developed. One, referred to as "Oscar" was made by [[Bell Labs]], using {{Convert|1.4|in|mm|abbr=on}} microphones inserted into the cheeks of a mannequin's head, and was demonstrated at the [[Century of Progress|World Fair]] in Chicago, in 1933. The Dutch firm, [[Philips]], also developed a binaural head, with the microphones located at the ears, which produced a better result. These early adaptations of the mannequins used in shops to model clothes led to the moniker "dummy head".

Over the course of the 20th century, advancements in microphone design and an understanding of the significance that the anatomy of the human ear played in the localization of sound led to further developments in the design of binaural heads.<ref>{{Cite web |title=Binaural Recording Technology: A Historical Review and Possible Future Developments |url=https://www.researchgate.net/publication/233582452 |archive-url=http://web.archive.org/web/20190129001035/https://www.researchgate.net/publication/233582452_Binaural_Recording_Technology_A_Historical_Review_and_Possible_Future_Developments |archive-date=29 January 2019 |website=ResearchGate |access-date=27 February 2025 }}</ref> Their use ranged from acoustic analysis, such as to record word scoring for speech intelligibility measurement,<ref>{{Cite journal |last1=Padilla-Ortiz |first1=A. L. |last2=Orduña-Bustamante |first2=Felipe |date=15 January 2021 |title=Binaural Speech Intelligibility Tests Conducted Remotely over the Internet Compared with Tests under Controlled Laboratory Conditions |url=https://www.sciencedirect.com/science/article/abs/pii/S0003682X20306782#:~:text=Intelligibility%20scores%20from%20trained%20subjects,-2,%20Reverb-2. |journal=Applied Acoustics |volume=172 |pages=107574 |doi=10.1016/j.apacoust.2020.107574 |issn=0003-682X }}</ref> hearing aid design,<ref>{{Cite web |author=Karl |date=18 June 2021 |title=High Drama in Audiology! A Brief History of Binaural Hearing Aid Fittings |url=https://hearingreview.com/hearing-loss/patient-care/hearing-fittings/a-brief-history-of-binaural-hearing-aid-fittings |website=The Hearing Review |access-date=27 February 2025 }}</ref> for music reproduction, and radio drama.

''[[The Demolished Man#Adaptations|Demolition]]'' (1973) was the first radio drama recorded using a dummy head.<ref>{{RalfBülow2013}}</ref>

In 1974, Virgin Records issued the first solo album by [[Tangerine Dream]]'s leader Edgar Froese, titled ''[[Aqua (Edgar Froese album)|Aqua]]''. The sleeve notes inform listeners that the tracks ''[[NGC 891]]'' and ''[[Upland (song)|Upland]]'' were recorded using a binaural head system developed by Gunther Brunschen. Listeners were advised to listen with stereo headphones. Although Edgar was keen to continue to use this system for subsequent recordings, it was abandoned because although it worked well through headphones, the improved sound quality did not translate adequately to a hi-fi speaker system.

In 1972, Neumann released the KU80 binaural head, which would eventually lead to the KU100 binaural head, which is widely used today.{{Citation needed|date=March 2025}}

In 1978, [[Lou Reed]] released the first commercially produced binaural pop record, ''[[Street Hassle]]'', a combination of live and studio recordings.<ref>{{cite news |last=Nusser |first=Dick |title=Arista Has 1st Stereo/Binaural Disk |url=https://books.google.com/books?id=piQEAAAAMBAJ&q=street+hassle+binaural&pg=PP1 |newspaper=Billboard |date=14 January 1978 |access-date=7 April 2014 }}</ref>

Binaural sound did not take off for music reproduction for consumers due to the 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 interested 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. Popular music typically involves a lot of electro-acoustic sources such as guitars and keyboards that when recorded in a studio setting would have little benefit from being recorded binaurally.{{Citation needed|date=March 2025}} Recordings that are of interest are live [[orchestra]]l performances, and ambient "environmental" recordings of city sounds, nature, and other such subject matters.

During the 1990s, electronic devices which used [[digital signal processing]] (DSP) to reproduce [[Head-related transfer function|HRTFs]] were made commercially available. These devices allowed the sound engineer to make it sound like a monophonic sound had been recorded with a binaural head, adjusting the apparent direction and proximity of a sound in real time. They were unusual and expensive, but would allow the sound engineer to alter special effects of prerecorded sounds quickly and conveniently. Software versions of these are now widely available.<ref>{{Cite web |title=Binaural Panning In Logic Pro |url=https://www.soundonsound.com/techniques/binaural-panning-logic-pro |website=SoundOnSound.com |access-date=27 February 2025 }}</ref>

The modern era has seen a resurgence of interest in binaural, partially due to the increased use of headphones, cheaper methods of recording and the general increased commercial interest in 360° audio technology.

In 2005, ''[[Aqua (Edgar Froese album)|Aqua]]'' was remixed for limited edition reissue in Germany and Japan, with an additional track ''[[Upland Dawn]]'' appended to the end of the CD.

In 2015, Singaporean singer-songwriter [[JJ Lin]] released his debut experimental album ''[[From M.E. to Myself]]'', using dummy head recording. This is also the first full album in the pop music industry to use this technology.<ref>NetEase Entertainment: JJ Lin's experimental album will be issued to create a true stereo surrounding sound http://ent.163.com/15/1125/07/B98I0FGK00031H0O.html</ref>

In 2015, the UK-based theatre company [[Complicité]] presented ''The Encounter'', where an audience of up to 850 people wore wired headphones listening to a binaural soundscape that featured both binaural recordings and the sound from a KU100 binaural head onstage, which relayed sound from the performer onstage. The show toured the world, and played on Broadway for several months, winning a [[Tony Awards|Tony Award]] for its sound design.<ref>{{Cite web |title=Gareth Fry and Pete Malkin to Be Honored with 2017 Special Tony Awards |url=https://www.tonyawards.com/news/gareth-fry-and-pete-malkin-to-be-honored-with-2017-special-tony-awards/ |website=TonyAwards.com |access-date=27 February 2025 }}</ref>

Binaural sound is often used in [[Virtual reality|Virtual Reality]], to help the user locate the source of something outside their field of vision. It also helps the user feel immersed in the experience by creating a realistic sonic landscape. Typically, this form of binaural sound is created by using monophonic recordings of sound that are processed through a binaural panner (and other processes that simulate distance, occlusion and acoustics) in real-time, based on where the user is facing.<ref>{{Cite web |last=Hayianni |first=Antonia |date=14 January 2020 |title=Why Binaural Audio Will Make VR the Star |url=https://hedgehoglab.com/why-binaural-audio-will-make-vr-the-star/ |website=HedgehogLab.com |access-date=27 February 2025 }}</ref>

The online [[ASMR]] community has widely employed binaural recordings.

Many of the major [[Music streaming service|music streaming]] services have started offering "Spatial Audio" versions of popular music. These are often mixed using [[Dolby Atmos]], which combines cinematic-style surround sound panning with object based panning. A smart phone, tablet or computer can be used to listen to these with headphones and the music track will be rendered into binaural sound on playback. Devices like [[Apple Inc.|Apple's]] [[AirPods Pro]] can be used to track the rotation of the users head and allow the music sources to rotate around the listener as they rotate their head.<ref>{{Cite web |title=Control Spatial Audio and head tracking |url=https://support.apple.com/en-gb/guide/airpods/dev00eb7e0a3/web |website=Apple Support |access-date=27 February 2025 }}</ref>

The increasing popularity of [[Podcast|podcasts]] has seen an increase in audio drama production, and there have been many produced using binaural recording, or by recording in mono and mixing those recordings using Dolby Atmos.<ref>{{Cite web |last=Nguyen |first=Anh |date=9 June 2022 |title=3D Audio Podcasts - The Ultimate Content Overview |url=https://www.vrtonung.de/en/spatial-audio-podcast-story-ultimate-content-overview/ |website=VRTONUNG - Virtual Reality Sound |access-date=27 February 2025 }}</ref>

==Recording techniques==
{{Listen
| filename     = BinauralPaper.ogg
| title        = Binaural recording of speech and paper crumpling
| description  = A binaural recording. The desired effect can be achieved only with [[stereo]] [[headphones]].
| format       = [[Ogg]]
}}

{{Listen
| filename     = One Man Rumba binaural audio demonstration.ogg
| title        = "One Man Rumba" binaural musical demonstration
| description  = A binaural recording. The desired effect can be achieved only with stereo headphones.
| format       = Ogg
}}

The simplest recording technique utilizes two small microphones, placed inside the ears of a human, a technique that can create very impressive first-person perspective recordings. The DPA 4560 was produced specifically for this type of recording.<ref>{{Cite web |title=4560 Binaural Headset Microphone |url=https://www.dpamicrophones.com/microphones/headset-and-earset/4560?variant=24 |website=DpaMicrophones.com |access-date=27 February 2025 }}</ref> This technique also clearly picks up the sounds of the person wearing the microphones, their breathing, clothing rustle, and any shifts in movement they may make, which can make it impractical for many types of recording.

More common is using a binaural head, also known as a dummy head, or ''Kunstkopf''.<ref>{{cite web |last=Sunier |first=J. |title=Binaural in Depth |url=http://www.binaural.com/SunBinArticle.html |url-status=dead |archive-url=https://web.archive.org/web/20200213191154/http://www.binaural.com/SunBinArticle.html |archive-date=13 February 2020 |access-date=4 February 2024 }}</ref> These typically have two microphones, {{Convert|15|cm|in|abbr=on}} apart, facing away from each other, with a head shaped mass between them. Typically these microphones will be embedded within the head with a silicone mould of a pair of ears in front of them. 

Some binaural microphones go further and include elements of the human torso, aiming to simulate how sounds are reflected off the shoulders and absorbed by body mass, known as Head and Torso Simulators (HATS). They often include more intricate detail, such as a mouth simulator.<ref>{{cite web |title=Type 4128-C Head and Torso Simulator (HATS) |url=https://www.bksv.com/en/transducers/simulators/head-and-torso/hats-type-4128c?tab=overview |website=BKSV.com |publisher=Brüel & Kjær |access-date=4 February 2024 }}</ref>

[[File:Lokalisation.svg|thumb|upright]]

The distance between the ears, the size, weight and shape of the head and ears aim to roughly approximate those of an average human, though as very few people are actually the average size<ref>{{Cite web |last=Weller |first=Craig |date=13 September 2021 |title=Average Fails Everyone |url=https://www.buildingtheelite.com/average-fails-everyone/ |website=Building the Elite |access-date=27 February 2025 }}</ref> this explains some of the variance in how dramatically a binaural effect is heard by different people. 

The aim is that each microphone records sound in the same spatial relationship: each signal having the relative inter-aural time, level and timbral differences that the two ears of a human being would have if they were situated in the same position as the binaural head.

[[File:Lautsprecherwiedergabe-Göttingen.svg|thumb]]

The recordings are then listened to through headphones, with the microphone from the left ear of the binaural head routed into the left headphone of the listener, and the microphone from the right ear routed into the right headphone of the listener. Our brains are then able to interpret the spatial cues within the recordings to create a three-dimensional soundscape within our consciousness<ref>{{Cite web |last=Malinverno |first=Matteo |date=28 June 2022 |title=What Is Binaural Audio? How Binaural Recording Works |url=https://splice.com/blog/what-is-binaural-audio/ |website=Blog {{!}} Splice |access-date=27 February 2025 }}</ref> because it mirrors our own hearing system. 

Like our ears, a binaural head records sounds from all directions: all the sounds of a space and a clear impression of the room acoustics. A binaural head can create exceptional recordings of acoustic music concerts, for example. However, it will also clearly record any noises the audience make too.

A binaural head also mirrors the limitations of the human hearing system too. so for example when a sound is directly in front of us. there is very little difference between the sound hitting our left ear and our right ear. If a sound is directly behind us, again there is very little difference between the sound hitting our left ear and our right ear. Without the help of our visual system, we can struggle to tell if something is directly in front of us, or directly behind us, based on our hearing system alone.

== Examples of binaural microphones ==

=== Brüel & Kjær Head and Torso Simulators (HATS) ===
[[File:Head and torso simulator.jpg|thumb|Brüel & Kjær head and torso simulator (HATS)]]

Designed to be used in-situ for [[Acoustical engineering|electro-acoustic]] tests on, for example, telephone handsets, headsets, audio conference devices, microphones, headphones, hearing aids and hearing protectors.<ref>{{Cite web |title=High-Frequency Head and Torso Simulator |url=https://www.bksv.com/en/transducers/simulators/head-and-torso/hats-type-5128 |website=Brüel & Kjær |access-date=5 December 2020 }}</ref> It includes soft moulded pinnae, nose, mouth and torso. Using an MRI scanner, Brüel & Kjær and DTU collected the geometries of a large population of human ears. By capturing the full ear canal geometry including the bony part adjoining the eardrum was, this data was post-processed to determine the average human ear canal geometry.<ref>{{Cite web |title=High Frequency HATS, Why? |url=https://www.bksv.com/en/knowledge/blog/sound/high-frequency-hats |access-date=12 May 2020 }}</ref>

=== Neumann KU 100 ===
The Neumann KU 100 is a simple design, with a more abstract representation of a head, and "realistic" ears. It is not customisable. The Neumann is a commonly used binaural microphone and features use by BBC R&D teams.<ref>{{Cite web |date=September 2012 |title=Binaural Broadcasting |url=https://www.bbc.co.uk/rd/projects/binaural-broadcasting |website=BBC.co.uk |access-date=7 September 2021 }}</ref>

=== G.R.A.S. Head & Torso Simulator KEMAR (HATS) ===
KEMAR was initially invented in collaboration with the audiological industry for the use of hearing aid development, and is still the de facto standard for this industry – however since then the usage of KEMAR has spread into a multitude of other industries like: telecommunications, hearing protection test, automotive development etc. KEMAR is designed using large statistical research to as close to the average human measurements as possible. Torso reflections have been seen to be a considerable contributor to creating a successful binaural recording.<ref>{{Cite journal |last=Han |first=H.L. |date=1991 |title=Measuring a Dummy Head in Search of Pinna Cues |url=http://www.aes.org/e-lib/browse.cfm?elib=5627 |journal=Journal of the Audio Engineering Society}}</ref> It has replaceable pinnae of different sizes and materials and sets of different type ear-canal simulators.

=== 3Dio range ===
The 3Dio range of binaural microphones feature two silicone ear (pinna) moulds separated by {{Convert|14|cm|in}}—slightly narrower than many binaural microphones. Microphones are placed inside the ears, and range from Primo EM172 in the Free Space and Free Space XLR models, to DPA 4060s in the Pro II model. The 3Dio range is considerably cheaper than the Neumann KU 100, for example, and used more on a consumer to prosumer level. There is no head mass between the ears, which allows the microphone to be lighter<ref>{{Cite web |title=Free Space XLR Binaural Microphone |url=https://3diosound.com/products/free-space-xlr-binaural-microphone?srsltid=AfmBOoqPjLCQrqPJpr9i8HbTppHR0FPa-Lr-sNd1LJ0L-Go_NUKzNtD1 |website=3Dio |access-date=27 February 2025 }}</ref> and more mobile, compared to other binaural microphones which can often weigh several kilograms.<ref>{{Cite web |title=KU 100 - Dummy Head |url=https://www.neumann.com/en-gb/products/microphones/ku-100 |archive-url=http://web.archive.org/web/20250222132444/https://www.neumann.com/en-gb/products/microphones/ku-100/ |archive-date=22 February 2025 |website=Neumann.com |access-date=27 February 2025 }}</ref>

=== Sound Professionals SP-TFB-2 and DPA 4560 headset microphone ===
These are both in-ear wearable stereo microphones, used like earphones, placed inside the human pinna. They use the user's pinna and head mass to create the binaural effect.<ref>{{cite web |last=Do |first=Tuan |date=5 April 2016 |title=Sound Professionals SP-TFB-2 Low-Noise In-Ear Binaural Microphones Review |url=http://www.techwalls.com/sound-professionals-in-ear-binaural-microphone-review/ |website=Techwalls }}</ref><ref>{{Cite web |title=4560 Binaural Headset Microphone |url=https://www.dpamicrophones.com/microphones/headset-and-earset/4560?variant=24 |website=DpaMicrophones.com |access-date=27 February 2025 }}</ref>

== Alternative methods of achieving binaural sound ==
Sounds that have been recorded in mono can be placed in a three-dimensional soundstage as if they had been recorded using a binaural head by using "binaural panning" software, such as [https://www.dear-reality.com/products/dearvr-pro-2 DearVR Pro 2] . The sound is processed using a complex mathematical algorithm imprinting inter-aural time, level, limited HRTF information, and optionally also room acoustics, onto the sound recording creating a binaural effect.<ref name="Liitola 2006">{{cite thesis |last=Liitola |first=T. |date=2006 |title=Headphone Sound Externalisation. Masters Thesis at Helsinki University of Technology, Finland }}</ref>

[[Ambisonics|Ambisonic recording]] techniques can also be used to generate binaural sound recordings.<ref>{{Cite web |title=Ambi Head HD - Converting ambisonic signals into 3D binaural audio |url=https://www.noisemakers.fr/product/ambi-head-hd/ |website=Noisemakers.fr |access-date=27 February 2025 }}</ref>

== Re-recording techniques ==
The technique of binaural re-recording is simple but has not been well established. It follows the same principles of Worldizing,<ref>{{Cite web |title=Worldizing |url=http://filmsound.org/terminology/worldizing.htm |website=Filmsound.org }}</ref> a technique used by film sound designers in which sound is played over a loudspeaker in a real-world location and then re-recorded, taking along all the aspects and characteristics of the real-world environment with it.<ref>{{Cite book |last=Burtt |first=Ben |title=Galactic Phrase Book & Travel Guide |date=2001 |publisher=Random House |location=New York |pages=136–137 }}</ref> 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 of how humans will hear multi-channel content. The soundtrack to a film, for example, could be recorded by the binaural microphone with all the environmental cues of the given location, as well as reverberations.

== Known issues ==

=== Averaging ===
The main focus of recording with a binaural head is to achieve a perfect binaural playback that is suited to all listeners. The problem arises that each human head has different shaped and sized features, making it very difficult to create a binaural effect compatible for everyone's ears. 

Averaging is done, either in the physical properties of binaural head microphones, or in the mathematical algorithm used to generate binaural sound using binaural panning software or ambisonic decoders. Some people may report hearing a very dramatic soundstage, while others may not. 

The effect that the shape of our head and our ears has on the sound we hear is part of what is called the [[Head-related transfer function|Head Related Transfer Function]], or HRTF.<ref name="Liitola 2006" /> Recent Apple [[iPhone Pro]]'s use the phone's camera and [[Lidar|LiDAR Scanner]] to create a 3D picture of the listener's ears, in order to create a [[Head-related transfer function|personalized HRTF]] file so that their own ear shape is factored into what they hear.

===Timbral issues===
In January 2012 BBC R&D worked together with [[BBC Radio 4]] to produce a binaural production of ''[[Private Peaceful]]''.<ref name="BBC Radio 4">{{Cite web |url=https://www.bbc.co.uk/blogs/radio4/2012/02 |title=BBC - Radio 4 and 4 Extra Blog |access-date=6 April 2017 }}</ref> The dramatization featured a reproduction of a 5.1 speaker system, and had 4 variations. At the start of each variation, the listener would hear a series of test signals allowing for a choice of which version gives them the best spatial experience. By doing this, BBC R&D have accepted that there will be variations on the success of the binaural reproduction, and therefore provided different mixes based on different sets of HRTF data. 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 (1-4) the listener thought was most successful.

During an interview with Chris Pike from BBC R&D in September 2012, Pike stated that "you may get good spatial impression but timbral coloration is often an issue".{{Citation needed|date=March 2025}} The issue of timbral coloration is mentioned in a large amount of spatial enhancement research and is sometimes seen as the outcome of the misuse or insufficient amount of HRTF data when reproducing binaural audio for example, or the fact that the end-user simply will not respond well to the collected HRTF data. Francis Rumsey states in the 2011 article "Whose head is it anyway?"<ref name=":2">{{Cite journal |last=Rumsey |first=Francis |date=2011 |title=Whose Head Is It Anyway? Optimizing Binaural Audio |url=https://secure.aes.org/forum/pubs/journal/?elib=15982 |journal=Journal of the Audio Engineering Society |volume=59 }}</ref> that "badly implemented HRTFs can give rise to poor timbral quality, poor externalisation, and a host of other unwanted results".<ref name=":2" /> Getting the HRTF data correct is a key point in making the final product a success, and possibly by making the HRTF data as extensive as possible, there will be less room for error such as timbral issues. The HRTFs used for ''Private Peaceful''<ref name="BBC Radio 4" /> were designed 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.{{Citation needed|date=March 2025}}

Juha Merimaa from [[Sennheiser]] Research Laboratories found that using HRTF filters to reduce timbral issues did not affect the spatial localization previously achieved using the data when tested on a panel of listeners.<ref>{{cite journal |last=Merimaa |first=Juha |date=2010 |title=Modification of HRTF Filters to Reduce Timbral Effects in Binaural Synthesis, Part 2: Individual HRTFs |url=http://www.aes.org/e-lib/browse.cfm?elib=15687 |journal=Journal of the Audio Engineering Society }}</ref> This explains that there are ways of reducing the effects of timbral issues on audio that have been processed with HRTF data, but this does mean further EQ 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 spatial 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.

=== Issues related to headphone quality ===
Ideal listening conditions will most likely be experienced with headphones designed to give an as flat frequency response as possible in order to reduce colouration of the audio the user is listening to. But many people may only have access to low quality headphones, which can result in them hearing something very different from what was intended, and that can muddy the spatial cues in the binaural audio.

=== Loudspeaker compatibility ===
While a binaural recording can be played on a stereo loudspeaker system, the spatial cues that should only be heard by the left ear are heard by both ears, rather than only by the ear on the corresponding side, as would be the case with headphones. Likewise, with the right ear spatial cues. This means the spatial effect of the binaural sound is compromised to a degree, and in some cases can sound a little odd. It is possible to convert binaural sound into a format that sits more naturally on a stereo loudspeaker system using software, such as Logic Pro's [https://support.apple.com/en-gb/guide/logicpro/lgcef240d802/mac Binaural Post Processing plug-in].

[[File:Lautsprecherwiedergabe.svg|thumb|none|A method to convert binaural sound for loudspeaker playback]]

==See also==
{{Commons category|Binaural recordings}}
* {{Annotated link|Binaural beats}}
* {{Annotated link|Binaural fusion}}
* {{Annotated link|Blumlein pair}}
* {{Annotated link|Dynamic Binaural recording}}
* {{Annotated link|Franssen effect}}
* {{Annotated link|Holophonics}}
* {{Annotated link|Precedence effect}}

==References==
{{Reflist|refs=

<ref name="Mattana 2017">{{cite web |first=Anthony |last=Mattana |title=The History of Binaural Audio, Part 1: The First Experiments, 1881-1939 |url=https://www.linkedin.com/pulse/history-binaural-audio-part-1-anthony-mattana/ |website=[[LinkedIn]] |date=31 July 2017 |access-date=25 September 2021 }}</ref>

}}

==Further reading==
* {{cite web |last=Lalwani |first=Mona |title=Surrounded by Sound: How 3D Audio Hacks Your Brain |url=https://www.theverge.com/2015/2/12/8021733/3d-audio-3dio-binaural-immersive-vr-sound-times-square-new-york |website=[[The Verge]] |date=12 February 2015 |access-date=1 March 2025 }}

==External links==
{{Wiktionary}}
* [https://www.pluviophile.com/rain-sounds-for-sleeping Examples of 3D binaural recordings]

{{Music technology}}

[[Category:Binaural recordings| ]]
[[Category:Autonomous sensory meridian response]]
[[Category:Microphone practices]]
[[Category:Stereophonic techniques]]