Safety Switch (Aaron L Hastings )

Subject: Safety Switch
From:    Aaron L Hastings  <hastinga(at)ECN.PURDUE.EDU>
Date:    Thu, 3 Mar 2005 11:41:52 -0500

Hello All,

I am wondering whether or not people include some type of safety switch
in their playback systems and if so what do they use?  We have a
playback system which consists of a LynxONE audio card, a TDT
attenuator, and Etymotic earphones.  We play sounds that are typically
as high as 70 dB SPL.  It is physically possible for our system to play
sounds greater than 90 dB and we would like to include a safegaurd so
that sounds sent to the attenuator, will not be played at levels greater
than XX dB.  Does anyone have any advice / experience with this issue.

Issues that I see at present:

    Anyting that we insert into the loop will increase noise

    A kill switch might also introduce a loud (damaging) noise depending
on how it is designed

   A compressor would introduce non-linearities and it may not be noticed
when it is actually affecting the signal and when not

Thanks for any input

Aaron