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.

Featured image for “Smartphones Have Microphones – Part 1”

Smartphones Have Microphones – Part 1

Marshall Chasin

There is a multitude of apps for Smartphones that can turn them into sound level meters, recording devices, playback devices, and even allow them to be coupled with external devices for hearing aids via Bluetooth or other wireless protocols. However, each step in the recording/playback/control pathways can add some error to the final measured result. Some of these errors are

Featured image for “The Occlusion Effect with Musicians’ Earplugs – Part 2”

The Occlusion Effect with Musicians’ Earplugs – Part 2

Marshall Chasin

In part 1 of this blog series, some characteristics of the occlusion effect were discussed. This refers to low frequency voice or musical energy (below 500 Hz) that is transduced (typically through the boney portion of the ear canal) and unless the ear is blocked up, is not heard- the low frequency sound energy escapes out of the unoccluded ear

Featured image for “The Occlusion Effect with Musicians’ Earplugs – part 1”

The Occlusion Effect with Musicians’ Earplugs – part 1

Marshall Chasin

A significant proportion of my clientele at the Musicians’ Clinics of Canada are for “second opinions”. Recently I had a referral where a trombone player was fit with ER-15 musicians’ earplugs but was complaining of the occlusion effect. The ear impressions were remade with a much longer earmold bore but the occlusion complaints remained. Indeed when I saw this man,

Featured image for “Speech is not a broadband signal… but music is.”

Speech is not a broadband signal… but music is.

Marshall Chasin

We tend to be biased, both in our training and in our technologies that we use. We tend to look at things based on spectra or frequencies. Phrases such as “bandwidth” and long term average speech spectrum show this bias. The long term average speech spectrum, with is averaged over time, is indeed a broad bandwidth spectrum made up of lower frequency

Happiness and Sadness in Music – part 2

Marshall Chasin

In part 1 of this blog series we had a discussion of the differences between major keys and minor keys and how this could be used to create a sense of happiness or sadness. A neurological and scientific description of emotion and creativity have long eluded researchers. What is it about a major scale that creates a positive and happy sensation, and

Happiness and Sadness in Music – part 1

Marshall Chasin

Happiness or sadness; joy or depression; creative or non-creative; good or bad- these are all emotions or states of mind that music can invoke. But the study of emotional and music is far from simple. And the study of emotion and music is more than a life’s worth of study. Researchers such as Dr. Frank Russo, and Dr. Charles Lim

Featured image for “American diplomats in Cuba report auditory issues…”

American diplomats in Cuba report auditory issues…

Marshall Chasin

On August 10, 2017 some American diplomats stationed in Cuba complained of some auditory and some vestibular symptoms. Recently one of our other editors at HearingHealthMatters.org, Brian Taylor, reported on some opinions from Dr. Jerry Punch about the possible cause. Ultrasound, infrasound, and other sources have been proposed as the possible cause of these complaints. There is no evidence in

Featured image for “Despite the benefits of SSRIs, tinnitus may be a side effect”

Despite the benefits of SSRIs, tinnitus may be a side effect

Marshall Chasin

Serotonin is a massively large molecule. In fact, it is so large that it cannot cross the blood brain barrier. We can’t simply take Serotonin orally or eat foods that have high levels of Serotonin- this won’t be able to get to the brain. Serotonin is like Las Vegas- what happens in Las Vegas, stays in Las Vegas….or so I

Featured image for “Does taking a break from loud noise or loud music really work? Part 2”

Does taking a break from loud noise or loud music really work? Part 2

Marshall Chasin

In part 1 of this blog series several issues were touched upon such as the relative uselessness of using gross measures such as puretone testing to determine the true nature of hearing loss from loud music or loud noise. In short, puretone hearing loss thresholds (and also otoacoustic emission (OAE) testing) are rather gross, albeit convenient, measures of hearing loss.

Featured image for “Does taking a break from loud noise or loud music really work? Part 1”

Does taking a break from loud noise or loud music really work? Part 1

Marshall Chasin

There have been a number of studies over the years trying to gauge the benefits, if any, of moderation and taking breaks away from loud noise or music. The short answer is that we are not really sure, but possibly. How is that for fence sitting? Intuitively it does make sense that reducing the overall “time weighted” average exposure of loud music