Unplugged Sound
"Auto-Protect Phenomena"
Anton Niedersteiner - Acoustic Sound Reinforcement & Audio Engineering
When people are exposed to very loud sound, their hearing becomes less sensitive at certain frequencies. Some have referred to this phenomena as an "auto protect mechanism". The use of such a term implies some sort of built-in ability of the human hearing system to protect itself from potentially damaging loud sounds. This may not be the case.
The following is a quote from Dr. Dennis Van Vliet, American Academy of Audiology:
"The acoustic reflex is a protective mechanism that quickly activates when the ear detects a loud sound. Contraction of the stapedius muscle reduces the efficiency of the middle ear system and effectively reduces the energy that reaches the cochlea. The reflex relaxes quickly when the noise ceases. Even with this protection, prolonged exposure to loud noise creates a temporary threshold shift (TTS) that is measurable, and lasts for several hours. Repeated exposure to noise causing TTS, will eventually lead to permanent hearing loss. Permanent hearing loss is due to physical damage in the cochlea (loss of hair cells). Temporary threshold shift is seen as a warning sign, not a protective phenomenon. Permanent hearing loss is a permanent compromise of a sensory function, and serves no protective function."
Certainly there is more than enough evidence to correlate hearing loss with noise exposure. Industrial workplaces are regulated to limit noise exposure or provide adequate hearing protection. If your ears are shutting down because it's too loud then heed their warning and protect your hearing.
Visit the Unplugged Sound Website: www.unpluggedsound.com
Back To Unplugged Sound Articles
Website by: Guy Langlois - Webmeister/Publisher Cosmic Debris, 610 Lambert Ave, Nanaimo, BC, V9R 3N8