Sound Talking at the Science Museum featured assorted speakers on sonic semantics

sound-talking-logo-large

On Friday 3 November, Dr Brecht De Man (Centre for Digital Music, Queen Mary University of London) and Dr Melissa Dickson (Diseases of Modern Life, University of Oxford) organised a one-day workshop at the London Science Museum on the topic of language describing sound, and sound emulating language. We discussed it in a previous blog entry, but now we can wrap up and discuss what happened.

Titled ‘Sound Talking‘, it brought together a diverse lineup of speakers around the common theme of sonic semantics. And with diverse we truly mean that: the programme featured a neuroscientist, a historian, an acoustician, and a Grammy-winning sound engineer, among others.

The event was born from a friendship between two academics who had for a while assumed their work could not be more different, with music technology and history of Victorian literature as their respective fields. When learning their topics were both about sound-related language, they set out to find more researchers from maximally different disciplines and make it a day of engaging talks.

After having Dr Dickson as a resident researcher earlier this year, the Science Museum generously hosted the event, providing a very appropriate and ‘neutral’ central London venue. The venue was further supported by the Diseases of Modern Life project, funded by the European Research Council, and the Centre for Digital Music at Queen Mary University of London.

The programme featured (in order of appearance):

  • Maria Chait, Professor of auditory cognitive neuroscience at UCL, on the auditory system as the brain’s early warning system
  • Jonathan Andrews, Reader in the history of psychiatry at Newcastle University, on the soundscape of the Bethlehem Hospital for Lunatics (‘Bedlam’)
  • Melissa Dickson, postdoctoral researcher in Victorian literature at University of Oxford, on the invention of the stethoscope and the development of an associated vocabulary
  • Mariana Lopez, Lecturer in sound production and post production at University of York, on making film accessible for visually impaired audiences through sound design
  • David M. Howard, Professor of Electronic Engineering at Royal Holloway University of London, on the sound of voice and the voice of sound
  • Brecht De Man, postdoctoral researcher in audio engineering at Queen Mary University of London, on defining the language of music production
  • Mandy Parnell, mastering engineer at Black Saloon Studios, on the various languages of artistic direction
  • Trevor Cox, Professor of acoustic engineering at University of Salford, on categorisation of everyday sounds

In addition to this stellar speaker lineup, Aleks Kolkowski (Recording Angels) exhibited an array of historic sound making objects, including tuning forks, listening tubes, a monochord, and a live recording of a wax cylinder. The workshop took place in a museum, after all, where Dr Kolkowski has held a research associateship, so the display was very fitting.

The full program can be found on the event’s web page. Video proceedings of the event are forthcoming.

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My favorite sessions from the 143rd AES Convention

AES_NY

Recently, several researchers from the audio engineering research team here attended the 143rd Audio Engineering Society Convention in New York. Before the Convention, I wrote a blog entry highlighting a lot of the more interesting or adventurous research that was being presented there. As is usually the case at these Conventions, I have so many meetings to attend that I miss out on a lot of highlights, even ones that I flag up beforehand as ‘must see’. Still, I managed to attend some real gems this time, and I’ll discuss a few of them here.

I’m glad that I attended ‘Audio Engineering with Hearing Loss—A Practical Symposium’ . Hearing loss amongst musicians, audiophiles and audio engineers is an important topic that needs more attention. Overexposure, both prolonged and too loud, is a major cause of hearing dage. In addition to all the issues it causes for anybody, for those in the industry, it affects their ability to work or even appreciate their passion. The session had lots of interesting advice.

The most interesting presentation in the session was from Richard Einhorn, a composer and music producer. In 2010, he lost much of his hearing due to a virus. He woke up one day to find that he had completely lost hearing in his right ear, a condition known as Idiopathic Sudden Sensorineural Hearing Loss. This then evolved into hyperacusis, with extreme distortion, excessive volume and speech intelligibility. In many ways, deafness in the right ear would have been preferred. On top of that, his left ear suffered otosclerosis, where everything was at greatly reduced volume. And given that this was his only functioning ear, the risk of surgery to correct it was too great.

Richard has found some wonderful ways to still function, and even continue working in audio and music, with the limited hearing he still has. There’s a wonderful description of them in Hearing Loss Magazine, and they include the use of the ‘Companion Mic,’ which allowed him to hear from many different locations around a busy, noisy environment, like a crowded restaurant.

Thomas Lund presented ‘The Bandwidth of Human Perception and its Implications for Pro Audio.’ I really wasn’t sure about this before the Convention. I had read the abstract, and thought it might be some meandering, somewhat philosophical talk about hearing perception, with plenty of speculation but lacking in substance. I was very glad to be proven wrong! It had aspects of all of that, but in a very positive sense. It was quite rigorous, essentially a systematic review of research in the field that had been published in medical journals. It looks at the question of auditory perceptual bandwidth, where bandwidth is in a general information theoretic and cognitive sense, not specifically frequency range. The research revolves around the fact that, though we receive many megabits of sensory information every second, it seems that we only use dozens of bits per second of information in our higher level perception. This has lots of implications for listening test design, notably on how to deal with aspects like sample duration or training of participants. This was probably the most fascinating technical talk I saw at the Convention.

There were two papers that I had flagged up as having the most interesting titles, ‘Influence of Audience Noises on the Classical Music Perception on the Example of Anti-cough Candies Unwrapping Noise’, and ‘Acoustic Levitation—Standing Wave Demonstration.’ I had an interesting chat with an author of the first one, Adam Pilch. When walking around much later looking for the poster for the second one, I bump into Adam again. Turns out, he was a co-author on both of them! It looks like Adam Pilch and Bartlomiej Chojnacki (the shared authors on those papers) and their co-authors have an appreciation of the joy of doing research for fun and curiousity, and an appreciation for a good paper title.

Leslie Ann Jones was the Heyser lecturer. The Heyser lecture, named after Richard C. Heyser, is an evening talk given by an eminent individual in audio engineering or related fields. Leslie has had a fascinating career, and gave a talk that makes one realise just how much the industry is changing and growing, and how important are the individuals and opportunities that one encounters in a career.

The last session I attended was also one of the best. Chris Pike, who recently became leader of the audio research team at BBC R&D (he has big shoes to fill, but fits them well and is already racing ahead), presented ‘What’s This? Doctor Who with Spatial Audio!’ . I knew this was going to be good because it involved two of my favorite things, but it was much better than that. The audience were all handed headphones so that they could listen to binaural renderings used throughout the presentation. I love props at technical talks! I also expected the talk to focus almost completely on the binaural, 3d sound rendering for a recent episode, but it was so much more than that. There was quite detailed discussion of audio innovation throughout the more than 50 years of Doctor Who, some of which we have discussed when mentioning Daphne Oram and Delia Derbyshire in our blog entry on female pioneers in audio engineering.

There’s a nice short interview with Chris and colleagues Darran Clement (sound mixer) and Catherine Robinson (audio supervisor) about the binaural sound in Doctor Who on BBC R&D’s blog, and here’s a youtube video promoting the binaural sound in the recent episode;

 

The Audiovisual bounce-inducing effect (Bounce, bounce, bounce… Part II)

Last week we talked about bouncing sounds. Its very much a physical phenomenon, but a lot has been made of a perceptual effect sometimes referred to as the ‘Audiovisual bounce-inducing effect.’ The idea is that if someone is presented with two identical objects moving on a screen in opposing direction and crossing paths, they appear to do just that- cross paths. But if a short sound is played at the moment they first intersect, they appear to bounce off each other.

I’ve read a couple of papers on this, and browsed a few more, and I’ve yet to see anything interesting here.

Consider the figures below. On the left are the two paths taken by the two objects, one with short dashes in blue, one with long dashes in red. Since they are identical (usually just circles on a computer screen), it could just as easily be the paths shown on the right.

AVbounceillusion

So which one is perceived? Well, two common occurrences are;

– Two objects, and one of them passes behind the other. This usually doesn’t produce a sound.
– Two objects, and they bounce off each other, producing the sound of a bounce.

If you show the objects without a sound, it perfectly matches the first scenario. It would be highly unlikely to perceive this as a bounce since then we would expect to hear something. On the other hand, if you play a short sound at the moment the two objects interact, even if it doesn’t exactly match a ‘bounce sound’, it is still a noise at the moment of visual contact. And so this is much more likely to be perceived as a bounce (which clearly produces a sound) than as passing by (which doesn’t). Further studies showed that the more ‘bounce-like’ the sound is, the more likely it is to be perceived as a bounce, and its less likely to be perceived as a bounce if similar sounds are also played when the objects do not intersect.

The literature gives all sorts of fanciful explanations for the basic phenomenon. And maybe someone can enlighten me as to why this is interesting. I suppose, if one begins with the assumption that auditory cues (even silence) do not play a role in perception of motion, then this may be surprising. But to me, this just seems to match everyday experience of sight and sound, and is intuitively obvious.

I should also note that in one of the papers on the ‘Audiovisual bounce-inducing effect’ (Watanabe 2001), the authors committed the cardinal sin of including one of the authors as a test subject and performing standard statistical analysis on the results. There are situations when this sort of thing may be acceptable or even appropriate*, but in which case one should be very careful to take that into account in any analysis and interpretation of results.

* In the following two papers, participants rated multrack audio mixes, where one of the mixes had been created by the participant. But this was intentional, to see whether the participant would rate their own mix highly.

And here’s just a few references on the audiovisual bounce inducing effect.

Grassi M, Casco C. Audiovisual bounce-inducing effect: When sound congruence affects grouping in vision. Attention, Perception, & Psychophysics. 2010 Feb 1;72(2):378-86.

Remijn GB, Ito H, Nakajima Y. Audiovisual integration: An investigation of the ‘streaming-bouncing’phenomenon. Journal of physiological anthropology and applied human science. 2004;23(6):243-7.

Watanabe K, Shimojo S. When sound affects vision: effects of auditory grouping on visual motion perception. Psychological Science. 2001 Mar;12(2):109-16.

Zeljko M, Grove PM. Sensitivity and Bias in the Resolution of Stream-Bounce Stimuli. Perception. 2017 Feb;46(2):178-204.

Sound Talking – 3 November at the London Science Museum

On Friday 3 November 2017, Dr Brecht De Man (one of the audio engineering group researchers) and Dr Melissa Dickson are chairing an unusual and wildly interdisciplinary day of talks, tied together by the theme ‘language describing sound, and sound emulating language’.

Despite being part of the Electronic Engineering and Computer Science department, we think about and work around language quite a lot. After all, audio engineering is mostly related to transferring and manipulating (musical, informative, excessive, annoying) sound and therefore we need to understand how it is experienced and described. This is especially evident from projects such as the SAFE plugins, where we collect terms which describe a particular musical signal manipulation, to then determine their connection with the chosen process parameters and measured signal properties. So the relationship between sound and language is actually central to Brecht’s research, as well as of others here.

The aim of this event is to bring together a wide range of high-profile researchers who work on this intersection, from maximally different perspectives. They study the terminology used to discuss sound, the invention of words that capture sonic experience, and the use and manipulation of sound to emulate linguistic descriptions. Talks will address singing voice research, using sound in accessible film for hearing impaired viewers, new music production tools, auditory neuroscience, sounds in literature, the language of artistic direction, and the sounds of the insane asylum. ‘Sounds’ like a fascinating day at the Science Museum!

Register now (the modest fee just covers lunch, breaks, and wine reception) and get to see

  • Maria Chait (head of UCL Auditory Cognitive Neuroscience lab)
  • Jonathan Andrews (on soundscape of the insane asylum)
  • Melissa Dickson (historian of 19th century literature)
  • Mariana Lopez (making film more accessible through sound)
  • David Howard (the singing voice)
  • Brecht De Man (from our group, on understanding the vocabulary of mixing)
  • Mandy Parnell (award winning mastering engineer)
  • Trevor Cox (categorising quotidian sounds)

In addition, there will be a display of cool sound making objects, with a chance to make your own wax cylinder recording, and more!

The full programme including abstracts and biographies can be found on www.semanticaudio.co.uk/events/soundtalking/.

What the f*** are DFA faders?

I’ve been meaning to write this blog entry for a while, and I’ve finally gotten around to it. At the 142nd AES Convention, there were two papers that really stood out which weren’t discussed in our convention preview or convention wrap-up. One was about Acoustic Energy Harvesting, which we discussed a few weeks ago, and the other was titled ‘The DFA Fader: Exploring the Power of Suggestion in Loudness The DFA Fader: Exploring the Power of Suggestion in Loudness Judgments.’ When I mentioned this paper to others, their response was always the same, “What’s a DFA Fader?” . Well, the answer is hinted at in the title of this blog entry.

The basic idea is that musicians often give instructions to the sound engineer that he or she can’t or doesn’t want to follow. For instance, a vocalist might say “Turn me up” in a soundcheck, but the sound engineer knows that the vocals are at a nice level already and any more amplification might cause feedback. Sometimes, this sort of thing can be communicated back to the musician in a nice way. But there’s also the fallback option; a fader on the mixing console that “Does F*** All”, aka DFA. The engineer can slide the fader or twiddle an unconnected dial, smile back and say ‘Ok, does this sound a bit better?’.

A couple of companies have had fun with this idea. Funk Logic’s Palindrometer, shown below, is nothing more than a filler for empty rack space. Its an interface that looks like it might do something, but at best, it just flashes some LEDs when one toggles switches and turns the knobs.

pal_main

RANE have the PI 14 Pseudoacoustic Infector . Its worth checking out the full description, complete with product review and data sheets. I especially like the schematic, copied below.

pi14bd.png

And in 2014, our own Brecht De Man  released The Wire, a freely available VST and AudioUnit plug-in that emulates a gold-plated, balanced, 100% lossless audio connector.

TheWire

Anyway, the authors of this paper had the bright idea of doing legitimate subjective evaluation of DFA faders. They didn’t make jokes in the paper, not even to explain the DFA acronym. They took 22 participants and divided them into an 11 person control group and an 11 person test group. In the control group, each subject participated in twenty trials where two identical musical excerpts were presented and the subject had to rate the difference in loudness of vocals between the two excerpts. Only ten excerpts were used, so each pair was used in two trials. In the test group, a sound engineer was present and he made scripted suggestions that he was adjusting the levels in each trial. He could be seen, but participants couldn’t see his hands moving on the console.

Not surprisingly, most trials showed a statistically significant difference between test and control groups, confirming the effectiveness of verbal suggestions associated with the DFA fader. And the authors picked up on an interesting point; results were far more significant for stimuli where vocals were masked by other instruments. This links the work to psychoacoustic studies. Not only is our perception of loudness and timbre influenced by the presence of a masker, but we have a more difficult time judging loudness and hence are more likely to accept the suggestion from an expert.

The authors did an excellent job of critiquing their results. But unfortunately, the full data was not made available with the paper. So we are left with a lot of questions. What were these scripted suggestions? It could make a big difference if the engineer said “I’m going to turn the vocals way up” versus “Let me try something. Does it sound any different now?” And were some participants immune to the suggestions? And because participants couldn’t see a fader being adjusted (interviews with sound engineers had stressed the importance of verbal suggestions), we don’t know how that could influence results.

There is something else that’s very interesting about this. It’s a ‘false experiment’. The whole listening test is a trick since for all participants and in all trials, there was never any loudness differences between the two presented stimuli. So indirectly, it looks at an ‘auditory placebo effect’ that is more fundamental than DFA faders. What were the ratings for loudness differences that participants gave? For the control group especially, did they judge these differences to be small because they trusted their ears, or large because they knew that loudness judging is the nature of the test? Perhaps there is a natural uncertainty in loudness perception regardless of bias. How much weaker does a listener’s judgment become when repeatedly asked to make very subtle choices in a listening test? There’s been some prior work tackling some of these questions, but I think this DFA Faders paper opened up a lot of avenues of interesting research.

The future of headphones

headphonememe

Headphones have been around for over a hundred years, but recently there has been a surge in new technologies, spurred on in part by the explosive popularity of Beats headphones. In this blog, we will look at three advances in headphones arising from high tech start-ups. I’ve been introduced to each of these companies recently, but don’t have any affiliation with them.

EAVE (formerly Eartex) are a London-based company, who have developed headphones aimed at the industrial workplace; construction sites, the maritime industry… Typical ear defenders do a good job of blocking out noise, but make communication extremely difficult. EAVE’s headphones are designed to protect from excessive noise, yet still allow effective communication with others. One of the founders, David Greenberg, has a background in auditory neuroscience, focusing on hearing disorders. He brought that knowledge to the company. He used his knowledge of hearing aids to design headphones that amplify speech while attenuating noise sources. They are designed for use in existing communication networks, and use beam forming microphones to focus the microphone on the speaker’s voice. They also have sensors to monitor noise levels so that noise maps can be created and personal noise exposure data can be gathered.

This use of additional sensors in the headset opens up lots of opportunities. Ossic are a company that emerged from Abbey Road Red, the start-up incubator established by the legendary Abbey Road Studios. Their headphone is packed with sensors, measuring the shape of your ears, head and torso. This allows them to estimate your own head-related transfer function, or HRTF, which describes how sounds are filtered as they travel from to your ear canal. They can then apply this filtering to the headphone output, allowing sounds to be far more accurately placed around you. Without HRTF filtering, sources always appear to be coming from inside your head.

Its not as simple as that of course. For instance, when you move your head, you can still identify the direction of arrival of different sound sources. So the Ossic headphones also incorporate head tracking. And a well-measured HRTF is essential for accurate localization, but calibration to the ear is not perfect. So their headphones also have eight drivers rather than the usual two, allowing more careful positioning of sounds over a wide range of frequencies.

Ossic was funded by a Kickstarter campaign. Another headphone start-up, Ora, currently has a Kickstarter campaign. Ora is a venture that was founded at Tandem Launch, who create companies often arising from academic research, and have previously invested in research arising from the audio engineering research team behind this blog.

Ora aim to release ‘the world’s first graphene headphones.’ Graphene is a form of carbon, shaped in a one atom thick lattice of hexagons. In 2004, Andre Geim and Konstantin Novoselov of the University of Manchester, isolated the material, analysed its properties, and showed how it could be easily fabricated, for which they won the Nobel prize in 2010. Andre Geim, by the way, is a colourful character, and the only person to have won both the Nobel and Ig Nobel prizes, the latter awarded for experiments involving levitating frogs.

graphene-headGraphene

Graphene has some amazing properties. Its 200 times stronger than the strongest steel, efficiently conducts heat and electricity and is nearly transparent. In 2013, Zhou and Zettl published early results on a graphene-based loudspeaker. In 2014, Dejan Todorovic and colleagues investigated the feasibility of graphene as a microphone membrane, and simulations suggested that it could have high sensitivity (the voltage generated in response to a pressure input) over a wide frequency range, far better than conventional microphones. Later that year, Peter Gaskell and others from McGill University performed physical and acoustical measurements of graphene oxide which confirmed Todorovic’s simulation results. Interestingly, they seemed unaware of Todorovic’s work.

graphene_speaker_640Graphene loudspeaker, courtesy Zettl Research Group, Lawrence Berkeley National Laboratory and University of California at Berkeley

Ora’s founders include some of the graphene microphone researchers from McGill University. Ora’s headphone uses a Graphene-based composite material optimized for use in acoustic transducers. One of the many benefits is the very wide frequency range, making it an appealing choice for high resolution audio reproduction.

I should be clear. This blog is not meant as an endorsement of any of the mentioned companies. I haven’t tried their products. They are a sample of what is going on at the frontiers of headphone technology, but by no means cover the full range of exciting developments. Still, one thing is clear. High-end headphones in the near future will sound very different from the typical consumer headphones around today.

Applause, applause! (thank you, thank you. You’re too kind)

“You must be prepared to work always without applause.”
―  Ernest Hemingway, By-line

In a recent blog entry , we discussed research into the sound of screams. Its one of those everyday sounds that we are particularly attuned to, but that there hasn’t been much research on. This got me thinking about what are some other under-researched sounds. Applause certainly fits. We all know when we hear it, and a quick search of famous quotes reveals that there are many ways to describe the many types of applause; thunderous applause, tumultuous applause, a smattering of applause, sarcastic applause, and of course, the dreaded slow hand clap. But from an auditory perspective, what makes it special?

Applause is nothing more than the sound of many people gathered in one place clapping their hands. Clapping your hands together is one of the simplest ways in which we can approximate an impulse, or short broadband sound, without the need for any equipment. Impulsive sounds are used for rhythm, for tagging important moments on a timeline, or for estimating the acoustic properties of a room. clappers and clapsticks are musical instruments, typically consisting of two pieces of wood that are clapped together to produce percussive sounds. In film and television, clapperboards have widespread use. The clapperboard produces a sharp clap noise that can be easily identified on the audio track, and the shutting of the clapstick at the top of the board can similarly be identified on the visual track. Thus, they are effective used to synchronising sound and picture, as well as to designate the starts of scenes or takes during production. And in acoustic measurement, if one can produce an impulsive sound at a given location and record the result, one can get an idea of the reverberation that the room will apply to any sound produced from that location.

Murri_artefacts_clapsticksclapstick
But a hand clap is a crude approximation for an impulse. Hand claps do not have completely flat impulse responses, are not completely omnidirectional, have significant duration and are not very high energy. Seetharaman and colleagues investigated the effectiveness of hand claps as impulse sources. They found that, with a small amount of additional but automated signal processing, the claps can produce reliable acoustical measurements.
Hanahara, Tada and Muroi exploited the impulse-like nature of hand claps for devising a means of Human-Robot Communication. The hand claps and their timing are relatively easy for a robot to decode, and not that difficult for a human to encode. But why the authors completely dismissed Morse code and all other simple forms of binary encoding is beyond me. And as voice recognition and related technologies continue to advance, the need for hand clap-based communication diminishes.
So what does a single hand clap sound like? This whole field of applause and clapping studies originated with a well-cited 1987 study by Bruno Repp, “The sound of two hands clapping.” He distinguished 8 hand clap positions;
Hands parallel and flat
P1: palm-to-palm
P2: halfway between P1 and P3
P3: fingers-to-palm

Hands held at an angle
A1: palm-to-palm
A2: halfway between P1 and P3
A3: fingers-to-palm
A1+: A1 with hands very cupped
A1-: A1 with hands fully flat

The figure below shows photos of these eight configurations of hand claps, excerpted from Leevi Peltola’s 2004 MSc thesis.

clap positions.png

Repp’s acoustic analyses and perceptual experiments mainly involved 20 test subjects who were each asked to clap at their normal rate for 10 seconds in a quiet room. The spectra of individual claps varied widely, but there was no evidence of influence of sex or hand size on the clap spectrum. He also measured his own clapping with the eight modes above. If the palms struck each other (P1, A1) there was a narrow frequency peak below 1 kHz together with a notch around 2.5 kHz. If the fingers of one hand struck the palm of the other hand (P3, A3) there was a broad spectral peak near 2 kHz.

Repp then tried to determine whether the subjects were able to extract information about the clapper from listening to the signal. Subjects generally assumed that slow, loud and low-pitched hand claps were from male clappers, and fast, soft and high-pitched hand claps were from female clappers. But this was not the case. The speed, intensity and pitch were uncorrelated with sex and thus it seemed that test subjects could correctly identify genre only slightly better than chance. Perceived differences were attributed mainly to hand configurations rather than hand size.

So much for individuals clapping, but what about applause. That’s when some interesting physics comes into play. Neda and colleagues recorded applause from several theatre and opera performances. They observed that the applause begins with incoherent random clapping, but then synchronization and periodic behaviour develops after a few seconds. This transition can be quite sudden and very strong, and is an unusual example of self-organization in a large coupled system. Neda gives quite a clear explanation of what is happening, and why.

Here’s a nice video of the phenomenon.

The fact that sonic aspects of hand claps can differ so significantly, and can often be identified by listeners, suggests that it may be possible to tell a lot about the source by signal analysis. Such was the case in work by Jylhä and colleagues, who proposed methods to identify a person by their hand claps, or identify the configuration (à  la Repp’s study) of the hand clap. Christian Uhle looked at the more general question of identifying applause in an audio stream.

Understanding of applause, beyond the synchronization phenomenon observed by Neda, is quite useful for encoding applause signals which so often accompany musical recordings- especially those recordings that are considered worth redistributing! And the important spatial and temporal aspects of applause signals are known to make then particularly tricky signals to encode and decode. As noted in research by Adami and colleagues, the more standard perceptual features like pitch or loudness do not do a good job of characterising grainy sound textures like applause. They introduced a new feature, applause density, which is loosely related to the overall clapping rate, but derived from perceptual experiments. Just a month before this blog entry, Adami and co-authors published a follow-up paper which used density and other characteristics to investigate the realism of upmixed (mono to stereo) applause signals. In fact, talking with one of the co-authors was a motivation for me to write this entry.

Upmixing is an important problem in its own right. But the placement and processing of sounds for a stereo or multichannel environment can be considered part of the general problem of sound synthesis. Synthesis of clapping and applause sounds was covered in detail, and to great effect, by Peltola and co-authors. They presented physics-based analysis, synthesis, and control systems capable of both producing individual hand-claps, or mimicking the applause of a group of clappers. The synthesis models were derived from experimental measurements and built both on the work of Repp and of Neda. Researchers here in the Centre for Digital Music’s Audio Engineering research team are trying to build on their work, creating a synthesis system that could incorporate cheering and other aspects of an appreciative crowd. More on that soon, hopefully.

“I think that’s just how the world will come to an end: to general applause from wits who believe it’s a joke.”
― Søren Kierkegaard, Either/Or, Part I

And for those who might be interested, here’s a short bibliography of applause and hand-clapping references;

1. Adami, A., Disch, S., Steba, G., & Herre, J. ‘Assessing Applause Density Perception Using Synthesized Layered Applause Signals,’ 19th International Conference on Digital Audio Effects (DAFx-16), Brno, Czech Republic, 2016
2. Adami, A.; Brand, L.; Herre, J., ‘Investigations Towards Plausible Blind Upmixing of Applause Signals,’ 142nd AES Convention, May 2017
3. W. Ahmad, AM Kondoz, Analysis and Synthesis of Hand Clapping Sounds Based on Adaptive Dictionary. ICMC, 2011
4. K. Hanahara, Y. Tada, and T. Muroi, “Human-robot communication by means of hand-clapping (preliminary experiment with hand-clapping language),” IEEE Int. Conf. on Systems, Man and Cybernetics(ISIC-2007),Oct2007,pp.2995–3000.
5. Farner, Snorre; Solvang, Audun; Sæbo, Asbjørn; Svensson, U. Peter ‘Ensemble Hand-Clapping Experiments under the Influence of Delay and Various Acoustic Environments’, Journal of the Audio Engineering Society, Volume 57 Issue 12 pp. 1028-1041; December 2009
6. A. Jylhä and C. Erkut, “Inferring the Hand Configuration from Hand Clapping Sounds,” 11th International Conference on Digital Audio Effects (DAFx-08), Espoo, Finland, 2008.
7. Jylhä, Antti; Erkut, Cumhur; Simsekli, Umut; Cemgil, A. Taylan ‘Sonic Handprints: Person Identification with Hand Clapping Sounds by a Model-Based Method’, AES 45th Conference, March 2012
8. Kawahara, Kazuhiko; Kamamoto, Yutaka; Omoto, Akira; Moriya, Takehiro ‘Evaluation of the Low-Delay Coding of Applause and Hand-Clapping Sounds Caused by Music Appreciation’ 138th AES Convention, May 2015.
9. Kawahara, Kazuhiko; Fujimori, Akiho; Kamamoto, Yutaka; Omoto, Akira; Moriya, Takehiro Implementation and Demonstration of Applause and Hand-Clapping Feedback System for Live Viewing,’ 141st AES Convention, September 2016.
10. Laitinen, Mikko-Ville; Kuech, Fabrian; Disch, Sascha; Pulkki, ‘Ville Reproducing Applause-Type Signals with Directional Audio Coding,’ Journal of the Audio Engineering Society, Volume 59 Issue 1/2 pp. 29-43; January 2011
11. Z. Néda, E. Ravasz, T. Vicsek, Y. Brechet, and A.-L. Barabási, “Physics of the rhythmic applause,” Phys. Rev. E, vol. 61, no. 6, pp. 6987–6992, 2000.
12. Z. Néda, E. Ravasz, Y. Brechet, T. Vicsek, and A.-L. Barabási, “The sound of many hands clapping: Tumultuous applause can transform itself into waves of synchronized clapping,” Nature, vol. 403, pp. 849–850, 2000.
13. Z. Néda, A. Nikitin, and T. Vicsek. ‘Synchronization of two-mode stochastic oscillators: a new model for rythmic applause an much more,’ Physica A: Statistical Mechanics and its Applications, 321:238–247, 2003.
14. L. Peltola, C. Erkut, P. R. Cook, and V. Välimäki, “Synthesis of Hand Clapping Sounds,”, IEEE Transactions on Audio, Speech, and Language Processing, vol. 15, no. 3, pp. 1021– 1029, 2007.
15. B. H. Repp. ‘The sound of two hands clapping: an exploratory study,’ J. of the Acoustical Society of America, 81:1100–1109, April 1987.
16. P. Seetharaman, S. P. Tarzia, ‘The Hand Clap as an Impulse Source for Measuring Room Acoustics,’ 132nd AES Convention, April 2012.
17. Uhle, C. ‘Applause Sound Detection’ , Journal of the Audio Engineering Society, Volume 59 Issue 4 pp. 213-224, April 2011