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.


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.


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.


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/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.

Female pioneers in audio engineering

The Heyser lecture is a distinguished talk given at each AES Convention by eminent individuals in audio engineering and related fields. At the 140th AES Convention, Rozenn Nicol was the Heyser lecturer. This was well-deserved, and she has made major contributions to the field of immersive audio. But what was shocking about this is that she is the first woman Heyser lecturer. Its an indicator that woman are under-represented and under-recognised in the field. With that in mind, I’d like to highlight some women who have made major contributions to the field, especially in research and innovation.

  • Birgitta Berglund led major research into the impact of noise on communities. Her influential research resulted in guidelines from the World Health Organisation, and greatly advanced our understanding of noise and its effects on society. She was the 2009 IOA Rayleigh medal recipient.
  • Marina Bosi is a past AES president of the AES. She has been instrumental in the development of standards for audio coding and digital content management standards and formats, including develop the AC-2, AC-3, and MPEG-2 Advanced Audio Coding technologies,
  • Anne-Marie Bruneau has been one of the most important researchers on electrodynamic loudspeaker design, exploring motion impedance and radiation patterns, as well as establishing some of the main analysis and measurement approaches used today. She co-founded the Laboratoire d’Acoustique de l’Université du Maine, now a leading acoustics research center.
  • Ilene J. Busch-Vishniac is responsible for major advances in the theory and understanding of electret microphones, as well as patenting several new designs. She received the ASA R. Bruce Lindsay Award in 1987, and the Silver Medal in Engineering Acoustics in 2001. President of the ASA 2003-4.
  • betzcohen-headshot_med_hrElizabeth (Betsy) Cohen was the first female president of the Audio Engineering Society. She was presented with the AES Fellowship Award in 1995 for contributions to understanding the acoustics and psychoacoustics of sound in rooms. In 2001, she was presented with the AES Citation Award for pioneering the technology enabling collaborative multichannel performance over the broadband internet.
  • crumPoppy Crum is head scientist at Dolby Laboratories whose research involves computer research in music and acoustics. At Dolby, she is responsible for integrating neuroscience and knowledge of sensory perception into algorithm design, technological development, and technology strategy.
  • Delia Derbyshire (1937-2001) was an innovator in electronic music who pushed the boundaries of technology and composition. She is most well-known for her electronic arrangement of the theme for Doctor Who, an important example of Musique Concrète. Each note was individually crafted by cutting, splicing, and stretching or compressing segments of analogue tape which contained recordings of a plucked string, oscillators and white noise. Here’s a video detailing a lot of the effects she used, which have now become popular tools in digital music production.
  •  Ann Dowling is the first female president of the Royal Academy of Engineering. Her research focuses on noise analysis and reduction, especially from engines, and she is a leading educator in acoustics. A quick glance at google scholar shows how influential her research has been.
  • Marion Downs was an audiometrist at Colorado Medical Center in Denver, who invented the tests used to measure hearing both In newly born babies and in fetuses.
  • Judy Dubno is Director of Hearing Research at the Medical University of South Carolina. Her research focuses on human auditory function, with emphasis on the processing of auditory information and the recognition of speech, and how these abilities change in adverse listening conditions, with age, and with hearing loss. Recipient of the James Jerger Career Award for Research in Audiology from the American Academy of Audiology and Carhart Memorial Lecturer for the American Auditory Society. President of the ASA in 2014-15.
  • thumb_FiebrinkPhoto3Rebecca Fiebrink researches Human Computer Interaction (HCI) and its application of machine learning to real-time, interactive, and creative domains. She is the creator of the popular Wekinator, which allows anyone to use machine learning to build new musical instruments, real-time music information retrieval and audio analysis systems, computer listening systems and more.
  • Katherine Safford Harris pioneered EMG studies of speech production and auditory perception. Her research was fundamental to speech recognition, speech synthesis, reading machines for the blind, and the motor theory of speech perception. She was elected Fellow of the ASA, the AAAS, the American Speech-Language-Hearing Association, and the New York Academy of Sciences. She was President of the ASA (2000-2001), awarded the Silver Medal in 2005 and Gold Medal in 2007.
  • Rhona Hellman was a Fellow of the ASA. She was a distinguished hearing scientist and preeminent expert in auditory perceptual phenomena. Her research spanned almost 50 years, beginning in 1960. She tackled almost every aspect of loudness, and the work resulted in major advances and developments of loudness standards.
  • Mara Helmuth developed software for composition and improvisation involving granular synthesis. Throughout the 1990s, she paved the way forward by exploring and implementing systems for collaborative performance over the Internet. From 2008-10 she was President of the International Computer Music Association.
  • Carleen_HutchinsCarlene Hutchins (1911-2009) was a leading researcher in the study of violin acoustics, with over a hundred publications in the field. She was founder and president of the Catgut Society, an organization devoted to the study and appreciation of stringed instruments .
  • Sophie Germain (1776-1831) was a French mathematician, scientist and philosopher. She won a major prize from the French Academy of Sciences for developing a theory to explain the vibration of plates due to sound. The history behind her contribution, and the reactions of leading French mathematicians to having a female of similar calibre in their midst, is fascinating. Joseph Fourier, whose work underpins much of audio signal processing, was a champion of her work.
  • Bronwyn Jones was a psychoacoustician at the CBS Technology Center during the 70s and 80s. In seminal work with co-author Emil Torrick, she developed one of the first loudness meters, incorporating both psychoacoustic principles and detailed listening tests. It paved the way for what became major initiatives for loudness measurement, and in some ways outperforms the modern ITU 1770 standard
  • Bozena Kostek is editor of the Journal of the Audio Engineering Society. Her most significant contributions include the applications of neural networks, fuzzy logic and rough sets to musical acoustics, and the application of data processing and information retrieval to the psychophysiology of hearing. Her research has garnered dozens of prizes and awards.
  • Daphne Oram (1925 –2003) was a pioneer of ‘musique concrete’ and a central figure in the evolution of electronic music. She devised the Oramics technique for creating electronic sounds, co-founded the BBC Radiophonic Workshop, and was possibly the first woman to direct an electronic music studio, to set up a personal electronic music studio and to design and construct an electronic musical instrument.
  • scalettiCarla Scaletti is an innovator in computer generated music. She designed the Kyma sound generation computer language in 1986 and co-founded Symbolic Sound Corporation in 1989. Kyma is one of the first graphical programming languages for real time digital audio signal processing, a precursor to MaxMSP and PureData, and is still popular today.
  • Bridget Shield was professor of acoustics at London Southbank University. Her research is most significant in our understanding of the effects of noise on children, and has influenced many government initiatives. From 2012-14, she was the first female President of the Institute of Acoustics.
  • Laurie Spiegel created one of the first computer-based music composition programs, Music Mouse: an Intelligent Instrument, which also has some early examples of algorithmic composition and intelligent automation, both of which are hot research topics today.
  • maryMary Desiree Waller (1886-1959) wrote a definitive treatise on Chladni figures, which are the shapes and patterns made by surface vibrations due to sound, see Sophie Germain, above. It gave far deeper insight into the figures than any previous work.
  • Megan (or Margaret) Watts-Hughes is the inventor of the Eidophone, an early instrument for visualising the sounds made by your voice. She rediscovered this simple method of generating Chladni figures without knowledge of Sophie Germain or Ernst Chladni’s work. There is a great description of her experiments and analysis in her own words.

The Eidophone, demonstrated by Grace Digney.

Do you know some others who should be mentioned? We’d love to hear your thoughts.

Thanks to Theresa Leonard for information on past AES presidents. She was the third female president. Will there be a fourth one soon?

Behind the spectacular sound of ‘Dunkirk’ – with Richard King: — A Sound Effect

The post Behind the spectacular sound of ‘Dunkirk’ – with Richard King: appeared first on A Sound Effect. Its an interesting interview giving deep insights into sound design and soundscape creation for film. It caught my attention first because of the mention of Richard King. But its not Richard King, Grammy award winning professor in sound recording at University of McGill. Its the other one, the Oscar award winning supervising sound editor at Warner Brothers Sound.

We collaborated with Prof. Richard King on a couple of papers. In [1], we conducted an experiment where eight songs were each mixed by eight different engineers. We analysed audio features from the multitracks and mixes. This allowed us to test various assumed rules of mixing practice. In the follow-up [2], the mixes were all rated by experienced test subjects. We used the ratings to investigate relationships between perceived mix quality and sonic features of the mixes.

[1] B. De Man, M. Boerum, B. Leonard, R. King, G. Massenburg and J. D. Reiss, ‘Perceptual Evaluation of Music Mixing Practices,’ 138th Audio Engineering Society (AES) Convention, May 2015

[2] B. De Man, B. Leonard, R. King and Joshua D. Reiss, “An analysis and evaluation of audio features for multitrack music mixtures,” 15th Int. Society for Music Information Retrieval Conference (ISMIR-14), Taipei, Taiwan, Oct. 2014

via Behind the spectacular sound of ‘Dunkirk’ – with Richard King: — A Sound Effect

Joshua D Reiss – Professor of Audio Engineering

Intelligent Sound Engineering are pleased to announce our lead academic, Joshua D Reiss has been promoted to Professor of Audio Engineering.

Professor Reiss holds degrees in Physics and Mathematics, and a PhD in Chaos Theory from Georgia Institute of Technology. He has been an academic with the Centre for Digital Music in the Electronic Engineering and Computer Science department at Queen Mary University of London since 2003. His primary focus of research is on state-of-the-art signal processing techniques for sound engineering, publishing over 160 scientific papers and authoring the book “Audio Effects: Theory, Implementation and Application” together with Andrew McPherson. Along with pioneering research into intelligent audio production technologies, Professor Reiss also focuses on state of the art sound synthesis techniques.

Professor Reiss is a visiting Professor at Birmingham City University, an Enterprise Fellow of the Royal Academy of Engineering and has been a governor of the Audio Engineering Society from 2013 to present.