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/.

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Our meta-analysis wins best JAES paper 2016!

Last year, we published an Open Access article in the Journal of the Audio Engineering Society (JAES) on “A meta-analysis of high resolution audio perceptual evaluation.”

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I’m very pleased and proud to announce that this paper won the award for best JAES paper for the calendar year 2016.

We discussed the research a little bit while it was ongoing, and then in more detail soon after publication. The research addressed a contentious issue in the audio industry. For decades, professionals and enthusiasts have engaged in heated debate over whether high resolution audio (beyond CD quality) really makes a difference. So I undertook a meta-analysis to assess the ability to perceive a difference between high resolution and standard CD quality audio. Meta-analysis is a popular technique in medical research, but this may be the first time that its been formally applied to audio engineering and psychoacoustics. Results showed a highly significant ability to discriminate high resolution content in trained subjects that had not previously been revealed. With over 400 participants in over 12,500 trials, it represented the most thorough investigation of high resolution audio so far.

Since publication, this paper was covered broadly across social media, popular press and trade journals. Thousands of comments were made on forums, with hundreds of thousands of reads.

Here’s one popular independent youtube video discussing it.

and an interview with Scientific American about it,

and some discussion of it in this article for Forbes magazine (which is actually about the lack of a headphone jack in the iPhone 7).

But if you want to see just how angry this research made people, check out the discussion on hydrogenaudio. Wow, I’ve never been called an intellectually dishonest placebophile apologist before 😉 .

In fact, the discussion on social media was full of misinformation, so I’ll try and clear up a few things here;

When I first started looking into this subject , it became clear that potential issues in the studies was a problem. One option would have been to just give up, but then I’d be adding no rigour to a discussion because I felt it wasn’t rigourous enough. Its the same as not publishing because you don’t get a significant result, only now on a meta scale. And though I did not have a strong opinion either way as to whether differences could be perceived, I could easily be fooling myself. I wanted to avoid any of my own biases or judgement calls. So I set some ground rules.

  • I committed to publishing all results, regardless of outcome.
  • A strong motivation for doing the meta-analysis was to avoid cherry-picking studies. So I included all studies for which there was sufficient data for them to be used in meta-analysis.  Even if I thought a study was poor, its conclusions seemed flawed or it disagreed with my own conceptions, if I could get the minimal data to do meta-analysis, I included it. I then discussed potential issues.
  • Any choices regarding analysis or transformation of data was made a priori, regardless of the result of that choice, in an attempt to minimize any of my own biases influencing the outcome.
  • I did further analysis to look at alternative methods of study selection and representation.

I found the whole process of doing a meta-analysis in this field to be fascinating. In audio engineering and psychoacoustics, there are a wealth of studies investigating big questions, and I hope others will use similar approaches to gain deeper insights and perhaps even resolve some issues.

Exciting research at the upcoming Audio Engineering Society Convention

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About five months ago, we previewed the last European Audio Engineering Society Convention, which we followed with a wrap-up discussion. The next AES  convention is just around the corner, October 18 to 21st in New York. As before, the Audio Engineering research team here aim to be quite active at the convention.

These conventions are quite big, with thousands of attendees, but not so large that you get lost or overwhelmed. Away from the main exhibition hall is the Technical Program, which includes plenty of tutorials and presentations on cutting edge research.

So here, we’ve gathered together some information about a lot of the events that we will be involved in, attending, or we just thought were worth mentioning. And I’ve gotta say, the Technical Program looks amazing.

Wednesday

One of the first events of the Convention is the Diversity Town Hall, which introduces the AES Diversity and Inclusion Committee. I’m a firm supporter of this, and wrote a recent blog entry about female pioneers in audio engineering. The AES aims to be fully inclusive, open and encouraging to all, but that’s not yet fully reflected in its activities and membership. So expect to see some exciting initiatives in this area coming soon.

In the 10:45 to 12:15 poster session, Steve Fenton will present Alternative Weighting Filters for Multi-Track Program Loudness Measurement. We’ve published a couple of papers (Loudness Measurement of Multitrack Audio Content Using Modifications of ITU-R BS.1770, and Partial loudness in multitrack mixing) showing that well-known loudness measures don’t correlate very well with perception when used on individual tracks within a multitrack mix, so it would be interesting to see what Steve and his co-author Hyunkook Lee found out. Perhaps all this research will lead to better loudness models and measures.

At 2 pm, Cleopatra Pike will present a discussion and analysis of Direct and Indirect Listening Test Methods. I’m often sceptical when someone draws strong conclusions from indirect methods like measuring EEGs and reaction times, so I’m curious what this study found and what recommendations they propose.

The 2:15 to 3:45 poster session will feature the work with probably the coolest name, Influence of Audience Noises on the Classical Music Perception on the Example of Anti-cough Candies Unwrapping Noise. And yes, it looks like a rigorous study, using an anechoic chamber to record the sounds of sweets being unwrapped, and the signal analysis is coupled with a survey to identify the most distracting sounds. It reminds me of the DFA faders paper from the last convention.

At 4:30, researchers from Fraunhofer and the Technical University of Ilmenau present Training on the Acoustical Identification of the Listening Position in a Virtual Environment. In a recent paper in the Journal of the AES, we found that training resulted in a huge difference between participant results in a discrimination task, yet listening tests often employ untrained listeners. This suggests that maybe we can hear a lot more than what studies suggest, we just don’t know how to listen and what to listen for.

Thursday

If you were to spend only one day this year immersing yourself in frontier audio engineering research, this is the day to do it.

At 9 am, researchers from Harman will present part 1 of A Statistical Model that Predicts Listeners’ Preference Ratings of In-Ear Headphones. This was a massive study involving 30 headphone models and 71 listeners under carefully controlled conditions. Part 2, on Friday, focuses on development and validation of the model based on the listening tests. I’m looking forward to both, but puzzled as to why they weren’t put back-to-back in the schedule.

At 10 am, researchers from the Tokyo University of the Arts will present Frequency Bands Distribution for Virtual Source Widening in Binaural Synthesis, a technique which seems closely related to work we presented previously on Cross-adaptive Dynamic Spectral Panning.

From 10:45 to 12:15, our own Brecht De Man will be chairing and speaking in a Workshop on ‘New Developments in Listening Test Design.’ He’s quite a leader in this field, and has developed some great software that makes the set up, running and analysis of listening tests much simpler and still rigorous.

In the 11-12:30 poster session, Nick Jillings will present Automatic Masking Reduction in Balance Mixes Using Evolutionary Computing, which deals with a challenging problem in music production, and builds on the large amount of research we’ve done on Automatic Mixing.

At 11:45, researchers from McGill will present work on Simultaneous Audio Capture at Multiple Sample Rates and Formats. This helps address one of the challenges in perceptual evaluation of high resolution audio (and see the open access journal paper on this), ensuring that the same audio is used for different versions of the stimuli, with only variation in formats.

At 1:30, renowned audio researcher John Vanderkooy will present research on how a  loudspeaker can be used as the sensor for a high-performance infrasound microphone. In the same session at 2:30, researchers from Plextek will show how consumer headphones can be augmented to automatically perform hearing assessments. Should we expect a new audiometry product from them soon?

At 2 pm, our own Marco Martinez Ramirez will present Analysis and Prediction of the Audio Feature Space when Mixing Raw Recordings into Individual Stems, which applies machine learning to challenging music production problems. Immediately following this, Stephen Roessner discusses a Tempo Analysis of Billboard #1 Songs from 1955–2015, which builds partly on other work analysing hit songs to observe trends in music and production tastes.

At 3:45, there is a short talk on Evolving the Audio Equalizer. Audio equalization is a topic on which we’ve done quite a lot of research (see our review article, and a blog entry on the history of EQ). I’m not sure where the novelty is in the author’s approach though, since dynamic EQ has been around for a while, and there are plenty of harmonic processing tools.

At 4:15, there’s a presentation on Designing Sound and Creating Soundscapes for Still Images, an interesting and unusual bit of sound design.

Friday

Judging from the abstract, the short Tutorial on the Audibility of Loudspeaker Distortion at Bass Frequencies at 5:30 looks like it will be an excellent and easy to understand review, covering practice and theory, perception and metrics. In 15 minutes, I suppose it can only give a taster of what’s in the paper.

There’s a great session on perception from 1:30 to 4. At 2, perceptual evaluation expert Nick Zacharov gives a Comparison of Hedonic and Quality Rating Scales for Perceptual Evaluation. I think people often have a favorite evaluation method without knowing if its the best one for the test. We briefly looked at pairwise versus multistimuli tests in previous work, but it looks like Nick’s work is far more focused on comparing methodologies.

Immediately after that, researchers from the University of Surrey present Perceptual Evaluation of Source Separation for Remixing Music. Techniques for remixing audio via source separation is a hot topic, with lots of applications whenever the original unmixed sources are unavailable. This work will get to the heart of which approaches sound best.

The last talk in the session, at 3:30 is on The Bandwidth of Human Perception and its Implications for Pro Audio. Judging from the abstract, this is a big picture, almost philosophical discussion about what and how we hear, but with some definitive conclusions and proposals that could be useful for psychoacoustics researchers.

Saturday

Grateful Dead fans will want to check out Bridging Fan Communities and Facilitating Access to Music Archives through Semantic Audio Applications in the 9 to 10:30 poster session, which is all about an application providing wonderful new experiences for interacting with the huge archives of live Grateful Dead performances.

At 11 o’clock, Alessia Milo, a researcher in our team with a background in architecture, will discuss Soundwalk Exploration with a Textile Sonic Map. We discussed her work in a recent blog entry on Aural Fabric.

In the 2 to 3:30 poster session, I really hope there will be a live demonstration accompanying the paper on Acoustic Levitation.

At 3 o’clock, Gopal Mathur will present an Active Acoustic Meta Material Loudspeaker System. Metamaterials are receiving a lot of deserved attention, and such advances in materials are expected to lead to innovative and superior headphones and loudspeakers in the near future.

 

The full program can be explored on the Convention Calendar or the Convention website. Come say hi to us if you’re there! Josh Reiss (author of this blog entry), Brecht De Man, Marco Martinez and Alessia Milo from the Audio Engineering research team within the Centre for Digital Music  will all be there.