Date   : Tue, 06 Aug 1985 09:10:59 EDT (Tue)
From   : Jeff Edelheit <edelheit@MITRE.ARPA>
Subject: Re: Environmental question..

I think some work in this area was published by the Human Factors Society and,
as I remember, the recommendation was for 60 db or less.  I don't remember
seeing any discussions regarding specific frequencies.

Jeff Edelheit
(edelheit@mitre)