Sound recording for the hard of hearing Part 5

This is the fifth in a series of blogs outlining some of what we know about optimal music recording.  When reading through these blogs one should be struck that we really know everything we need to know already when it comes to recording.  In some cases, what was learned in our first year audiology class provided  “obvious” recording cues (such as ensuring a wide bandwidth) and in other cases, the information and concepts have been learned but may have applied to fields other than music recording.

In the last blog we talked about the similarities between audiologists and sound recording engineers (and music composers).  Audiologists and sound recording engineers really use similar hardware and controlling software.  The engineers call their device a digital audio workstation or DAW.  Audiologists call theirs NOAH.  Both are capable of adjusting gain, output, frequency response, and compression and release times of compressors and expanders.  Given the differing histories of these two groups it is understandable that we don’t chat with our engineering colleagues as much as perhaps we should.

I have referred to audiologists as sound engineers for the hard of hearing and sound engineers as recorders of music for those with normal hearing.  However, what about our clients who have a hearing loss and who would like access to music?

It is now within the purview of both audiologists and sound engineers to be able to compose and record music for young children with a congenital hearing loss.  Take, for example, the case of a child who only has residual hearing at 250 Hz and 500 Hz (with no measurable responses above that).  Even with the best hearing aids out there, this child would be able to hear only the fundamental energy of the music and none of the harmonic structure.

Recall that middle C is just above 250 Hz and the C above that is roughly 500 Hz, this hard of hearing child would only have access to the far left side of a piano keyboard, and would only really obtain pure tones (the fundamental) above that.

Unveiled at the 7th Widex Congress of Paediatric Audiology that took place at Lake Como in Italy on 3-4 June 2012 was just such a CD for hard of hearing children.  I must admit to some bias (and pride) since the music was composed by my son Shaun, who is a senior at the Berklee School of Music in Boston.

The characteristics of the music that Shaun wrote were actually quite simple.  He composed music where the fundamental and the first two (and in some cases three) harmonics were below 500 Hz.  In one piece, there was a bass clarinet lead instead of a violin or flute lead.  Spectrographic analysis showed that to the extent that it could be done, most of the relevant music was within an accessible range for hard of hearing children with “corner audiogram” hearing statuses.

It was not without its problems, and this is where audiological input was required.  For some of the music, there was too much low-frequency emphasis, such that the noise reduction settings of the hearing aids confused the music for noise.  This was remedied by high-passing the music above 100 Hz.

More such interactions between sound engineers, music composers, and audiologists in the future will undoubtedly increase accessibility of music to those with a hearing loss.


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.