Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!UDEL.EDU!Mills
From: Mills@UDEL.EDU
Newsgroups: comp.protocols.tcp-ip
Subject: Re:  human factors aspects of echo delay
Message-ID: <8905041101.aa24075@huey.udel.edu>
Date: 4 May 89 15:01:10 GMT
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Amanda,

In my obstreperous youth I happened to be a real live disk jockey for
commercial radio working my way through school. We had an initiation
rite for new guys that involved earphones, a tape machine and a live
news broadcast. The victim, wearing cans and listening to himself
on a live broadcast, was switched without warning to a tape playback
delayed maybe 250 milliseconds, which of course instantly discombobulated
him. It happened to me, of course, with my reaction ripping the cans
off my head after stumblebumming the six o'clock news and with the
control-room guys laughing their heads off. My conclusion is that about
250 ms is just about the resonance point of the the human feedback control
system.

Dave