Marshall Chasin

Marshall Chasin, AuD, is an audiologist and the Director of Auditory Research at the Musicians’ Clinics of Canada, Adjunct Professor at the University of Toronto (in Linguistics), Associate Professor in the School of Communication Disorders and Sciences at the Western University. He is the author of over 200 articles and 7 books including Musicians and the Prevention of Hearing Loss. Dr. Chasin has been the recipient of many awards over the years including the 2012 Queen Elizabeth II Silver Jubilee Award for service to Canada and the Canada 150 Medal in 2017. He has developed a new TTS app called Temporary Hearing Loss Test app.

Beats, Fuzziness, and Tonality

Marshall Chasin

Actually, Psycho-acoustics is one of the more fascinating area of audition, and I must admit that I use what I learned in those pre-dawn classes every day of my clinical life. The question arises; assuming that the two notes are in the same or complimentary keys, when do two simultaneous notes sound good together? Or conversely, when do two notes make

Music and the PCAST Recommendations -Part 4

Marshall Chasin

So…. when is a hearing aid prescription a hearing aid prescription? Hearing aid prescription is a regulated act in many jurisdictions around the world. Regulation is not an issue unto itself- the important issue is why did local jurisdictions want hearing aid prescriptions to be regulated in the first place. Yes, regulations can change, but the reasons behind them generally

Music and the PCAST Recommendations- Part 3

Marshall Chasin

The most important element in a hearing aid fitting is the OSPL90. This, according to ANSI 3.22, is the maximum sound that can be transduced with a 90 dB SPL input. The OSPL90 is a well-defined measure that provides information on the maximum output, and when combined with other measuring tools such as the Real Ear Coupler Difference (RECD) can

Music and the PCAST Recommendations- Part 2

Marshall Chasin

In part 1 of this blog series, several general issues were touched on regarding the simplistic nature of the first and second PCAST recommendations. In summary, both were predicated on referring to a “basic” hearing aid as one that is of a mild to moderate degree and one that could equally (or almost equally in the eyes of the PCAST

Restez à l’écoute La campagne de protection de l’ouïe

Marshall Chasin

Par Gordana Mosher, Coordonnatrice des relations publiques, SCO Journée internationale de la sensibilisation à l’ouïe, la SCO a parcouru les rues pour sa campagne de protection de l’ouïe, Keep on Listening (Restez à l’écoute). Des bénévoles de la SCO et de Manifest Communications, un chef de file canadien du changement social, se sont adressés à de jeunes gens qui portaient

Music and the PCAST Recommendations: Part 1

Marshall Chasin

Most of my blog entries are not particularly political. They can, and do touch on certain advocacy items if I feel that it may affect the accessibility of services or products, but by in large, I have situated my blog entries in more of a technical and clinical framework. The recommendations of the President’s Council of Advisors on Science and

In Search of Negative Gain

Marshall Chasin

From time to time we see clients clinically who have very significant sensory, and possibly neural, damage. The question always arises in my mind whether to amplify the sound reaching that ear, or to remove the ear from the auditory environment. There is no clear test for this. In some cases it can be the result of end-stage Meniere’s disease,

Ultrasonics – Part 2

Marshall Chasin

Last week’s blog was about acoustic tractor beams and even though only a measly 9 watts was required, it did use a 40,000 Hz signal at very high sound levels. A stimulus such as 40,000 Hz (40 kHz) is considered an ultrasonic sound because it exceeds the hearing threshold of normal hearing young people. Unfortunately I can only hear up

Prudence D’abord

Marshall Chasin

par Carol Trottier La prudence est de mise dans certaines circonstances ! Voici quelques trucs que les personnes malentendantes peuvent poser par mesure de sécurité. Enregistrez-vous auprès de la caserne de pompier de votre voisinage. En cas de feu, les pompiers sauront agir en conséquence. Procurez-vous un détecteur de fumée qui émet des odeurs ou qui est branché à un

Acoustic Tractor Beam- part 1

Marshall Chasin

What consumes only 9 watts of power and is at 40 kHz? Well, I think we would all agree that this sounds just like an acoustic tractor beam. Unfortunately it can’t grab onto Romulan battle cruisers or interstellar Ferengi cargo ships because it is acoustic, and other than Battle Star Galactica, there is no sound in space. (The producers of