He removes his hearing aid for music

This is from an August 14, 2011 article written by Mike Kepka of the San Francisco Chronicle in his column “The City Exposed”….

Dr. Ephraim Engleman takes out the hearing aid in his left ear. He slides his bow down the thickest string of his beloved violin. A faint smile moves over his face as his eyes dance over the score of the Haydn quartet he and three others are working through tonight. “It’s hard to describe. It’s thrilling,” he said, grateful to still hear his quartet during his 100th year on Earth.

From the first line we see that Dr. Engleman removes his hearing aid. And given the technology of today’s hearing aids this is probably a good strategy.  This is in part based on equal loudness contours; the inability of most hearing aids to replace the mid and low frequency “natural hearing” caused by the attenuation of the ear mold; frequently inappropriately set hearing aid software; and of course, my favorite topic, distortion caused by the front end of the hearing aid because of the more intense inputs of music.

Either Dr. Engleman is a closet audiologist or he just knows what seems to work.  Equal loudness contours can vary depending on how they are measured as well as the various stimuli that are used but the bottom line is that typically less gain is required for more intense inputs than for softer inputs.  Holding a violin near his left ear yields inputs in excess of 100 dB SPL, much greater than for speech.  Even if the hearing aid provided 0 dB of gain, a 100 dB SPL output may be more than sufficient for this gentleman.  So removing it is not a bad idea.

The following suggested levels of gain for quiet speech (50 dB SPL), medium speech (65 dB), and loud speech (80 dB) are shown, but these can be rewritten at quiet music (65 dB), medium music (80 dB), and loud music (95 dB).

Input levels Amount of gain for a 50 dB HL loss
Soft speech (50 dB) 24 dB
Medium speech (65 dB) 17 dB
Loud speech (80dB) 9 dB
Loud music (95 dB) 1 dB

Simply stated, a person with a 50 dB HL hearing loss may require significant amplification for speech but require virtually no amplification for softer levels such as music.

And what about those hearing aid fittings that are designed to have occluding or semi-occluding earmold couplings?  Well, I would suggest three things… verify, verify, verify.  Make sure that with the proper settings of the hearing aid, especially at higher levels, that what goes into the hearing aid, at least, comes out of it.  Unity gain at high levels is typically the goal, especially for music and for most hearing losses that are moderate or less in degree.  A 90 dB SPL input in the lower frequencies to a hearing aid should be at least 90 dB SPL on the output side.

Go ahead and listen to music, and it’s OK to remove the hearing aids, at least as an experiment.

About Marshall Chasin

Marshall Chasin, AuD, is a clinical and research audiologist who has a special interest in the prevention of hearing loss for musicians, as well as the treatment of those who have hearing loss. I have other special interests such as clarinet and karate, but those may come out in the blog over time.