View single post by sparks
 Posted: Sep 17th, 2013 04:40 PM
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sparks



Joined: Jan 15th, 2008
Location: New Zealand
Posts: 77
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Hi Jan and all,
There has been experimentation done to identify the entry point for voices. The results that have come from my attempts and those of other researchers indicate that multiple entry points are likely, and that an accumulative process is in effect.

Bill Weisensale in the 1980s conducted an isolation experiment that went something like this:
Connect the audio output of an AM radio directly to the line input of a tape recorder. Set recorder to record mode, tune the radio so it is tuned to a blank spot in between stations. Test there is no recorded radio reception by playing back a recording. Then place the setup in a sealed metal drum while the recorder is recording the static. Result: voices on playback are evident once retrieved from the drum. Conclusion: Voices not acoustic in origin (no mic used) and is not a radio signal. Likely to be direct influence within the electronics that shapes internal or radio received/ generated noise into a voice.
Another experiment. A stereo recorder, one line input channel electrically patched to radio output. The other (mic) channel has mic and it listens to the radio speaker. Record while setting both channels to be the same level. Result: both channels record voices but the channel with mic and speaker has clearer reception. Conclusion: the speaker mic interface adds value to reception that is already happening.

Compare the two experiments to see it is a complex question to answer, but some clues are evident.
regards,
JEFF