SNR Loss: “I Can Hear What People Say, But I Can’t Understand Them”
Killion, MC
The Hearing Review 4(12), 8-14, 1997.
SOMETHING ABOUT MEAD
Although not an audiologist, Mead was always focused on helping people hear better. Sometimes this involved designing new hearing devices or testing equipment, and sometimes, as in this case, it involved clinical education. In this excellent 'Fitting Tips' article from the Hearing Review, Mead presented a compelling case for assessing clarity loss separately from sensitivity loss, arguing that the two are relatively independent and that both should inform counselling. And Mead was a great teacher. He carefully unpacked the idea using clinical examples and figures, and explained how this all related to hearing aids. But telling clinicians why they should use speech-in-noise measures was not enough; in later years he would also develop a way to make this kind of testing easier in the clinic—the QuickSIN.
SUMMARY
This article stressed the importance of understanding that hearing loss involves two components: a loss of hearing sensitivity (hearing threshold elevation) and a loss of clarity (speech-in-noise (SNR) threshold elevation or 'SNR loss'). Speech-in-noise testing often reveals clarity deficits (SNR loss) that may be related to inner hair cell loss. Several cases were presented to illustrate the relative independence of these two loss components. It was recommended that clinicians assess both types of loss and include them in counselling. The article also explained that hearing aid technology had improved (at the time of the article, in the late 1990s) and could now effectively compensate for hearing threshold elevation without degrading the signal quality. Moreover, technologies such as directional microphones and FM systems could now be used to help compensate for SNR loss.
Annotated by: Steve Aiken