Components for Protecting and Optimizing Good Hearing

In November 2010 I had the pleasure to give a lecture at the International Convention of Sound Designers on the marvelous capabilities of the human ear. The meeting took place at the Congress Center in Leipzig, Germany. One of the reasons for this topic is the fact that the EU-standards for protecting the ear at the workplace create much trouble for sound designers. The acoustic conditions at their work places are declared harmful, but sound designers hear much better than the normal population. This discrepancy is caused by wrong assumptions of the standard.

Here is the abstract.

Studies on the auditory performance of entire groups of persons reveal that people ex-
posed to low sound levels do not generally hear better than those living and working in
loud acoustic conditions. Hence, the basis for world-wide standards to protect the ear
are incorrect and insufficient. Reason for this are powerful neural mechanisms of the
auditory system that is working hard to prevent noise-induced auditory damage and to
optimize various aspects of hearing. Studying special conditions at the workplace, as
well as at places related to hobbies and other activities, indicates the existence of several
such functional components. Overall sensitivity of hearing can apparently be reduced in
loud environments. Anticipating exposure to short loud events the auditory system can
rapidly reduce the sensitivity. Masking effects of low frequencies can be scaled down in
order to focus on high frequencies. Strong low-frequency components protect against si-
multaneous high-frequency noise. Very short impulses are more harmful than longer ones.
Most dangerous are rarely occurring unexpected powerful impulses. Auditory threshold
and threshold of pain are both subject to training. Damage caused by impulses result in
characteristic forms of audiograms. — The auditory neural system can be damaged or
reprogrammed by a single powerful impulse.

The article is published under the CC BY-NC-SA 3.0 license.

You can download the original file, which is about 49 MB, or a compressed version of about 12 MB, lacking clickable links.

Children’s Toys

Why children’s toys?
Damages to hearing, caused by noise, do not heal, and so they are called permanent. Hence, such injuries pile up. Protecting the ear of children can delay – or even avoid – the development of such a „damage pile“. Adults working in loud industries, or serve in the military, have experts that care about their environment, an advantage children do not have.

The auditory system
It consists of the two ears plus parts of the central nervous system, a marvelously effective neural machinery. Continue reading