From: utzoo!decvax!cca!hplabs!hao!menlo70!sytek!zehntel!teklabs!donch@sri-unix Newsgroups: net.cycle Title: Re: headphones and helmets Article-I.D.: teklabs.1391 Posted: Wed Sep 15 12:39:28 1982 Received: Wed Sep 22 11:04:05 1982 Recent discussions here concerning headphones and helmets brings to mind a discussion I had with a grad student audiologist. This fellow was a grad student at Portland State University (Oregon) several years ago and was doing massive testing of people chosen at random for his thesis. He told me that one result of his tests was to be able to identify a motorcyclist based solely on the standard full-spectrum audio test. Apparently cyclists have reduced sensitivity in a particular region of the sound spectrum. His conclusion was that motorcycles were terribly loud machines, hence a danger to hearing. As most of you know, the engine is invariably drowned out by wind noise at speed, and it is this that certainly causes the reduced sensitivity he noted. My experience over the past 15 years has prompted me to use the expandable foam type ear plugs whenever I take a protracted ride. It saves me from a very obvious hearing suppression that otherwise occurs whenever I don't use earplugs on long trips (> 1 hr.). For many years my helmet of choice was a Bell Magnum. When I finally bought a Nava (it was the only full-coverage helmet to fit my strangely shaped head), the noise reduction was enormous. The Magnum let an incredible amount of self-generated noise in. Wearing glasses compounded the problem because it destroyed the padding seal in front of the ears. I bought a cheap set of "Walkman" type earphone that will fit in the space available in my Nava. They haven't been installed yet largely because of hearing-loss concerns as described in previous articles. The point is important on these type of phones because they are specifically designed not to mask external sound. Earphones that completely surround the ear and seal to the side of the head DO mask sound and should be the phones of choice for ear-conscious people. However, I haven't found any that fit inside my helmet or that I'm willing to gamble bucks on for an experiment after cutting them up to fit. Perhaps the main point of all this is: hearing loss is insidious. And once it occurs, you don't get it back in almost all cases. Food for thought. Don Chitwood Tek Labs, Tektronix