I am trying to help a friend who is researching whether noise cancelling head phones may help our instrument and controls technicians working in our noisy power plant. I appologize if this discussion may not be directly appropriate for the ultrasonic discussion board. I routinely post on the vibration discussion board...and hoped this may be a good source of information.

My friend identified two types of headphones, one by Sony and the other from JVC. Each identifies the range of active noise cancelling from 100 to 1500Hz. I have learned that human hearing picks up from 20 - 20,000Hz. My initial guess was that the frequency range specified for the head phones was too small for the full range affecting the wearer.

My friend is simply trying to research a way to minimize background noise and thus improve communication between workers in a noisy environment. Any specific advice on use of noise cancelling headphones...or advice to solve communication difficulties otherwise...is appreciated.

Thanks in advance,
George D'Entremont

http://www.activeforever.com/p-1788-noisebuster-electro...safety-earmuffs.aspx

Check these out and let me know what you think.
J

George,

There are plastic earplug speakers available that have a 20db or so noise reduction. They have the micro connector like you would plug into an MP3 player. I saw them in a catalog from Safetech, I think and they were not terribly expensive.

They aren't noise canceling, but may serve the purpose. My concern would be the radio squelch that close to the ear and the possibility of accidentally turning up the volume.

Look at something called "muscians ear buds". They seat deep in the ear canal to shut out ambient noise, but have very high quality speakers built into them. Two brands I am familiar with are Etymotic and Shure brands. Then for more noise reduction, wear a good set of over the ear muffs such as from Howard Leight.