Device Shuts Off Radio Advertising; Tunes in Music (Apr, 1934)
Is there any way this could possibly have worked? It seems like way too subtle a problem to solve just by matching certain frequencies. I’m sure you could program a computer to do a pretty good job of this now, but even that would have problems. And even if it worked, who’s to say a commercial can’t have music?

Device Shuts Off Radio Advertising; Tunes in Music
RADIO listeners who dislike advertising announcements and long speeches will welcome a new invention that automatically shuts off voice programs.
The device, known as the “radio advertising eliminator,” will operate the radio only when musical programs are coming over the air. Just as soon as any voice announcement is made from the station, the radio receiver is turned off and is not turned on again until the musical program resumes.
The radio voice eliminator was invented by Dr. Gledson W. Kenrick, of Tufts College. It was demonstrated at the annual meeting of the American Association for the Advancement of Science. Of course, when the listener wants to listen to speeches or mixed programs, the device must be disconnected from the receiver.It is believed that the new device uses a vibrating reed tuned to a predominant voice frequency to operate a relay which turns the set on and off.




Actually, It’s more or less doable. More than going after a certain frequency I’d be more inclined to believe it went after a certain average amplitude in the incoming signal – commercials would be “louder” than the typical programming, so it would sense that and off it went.
I’ve seen similar circuits used for automatic level controls back in the Dark Ages…8)
Alan
I want one !
I don’t mind manually hitting the mute button, but an automatic device to kick the radio or TV OUT of mute at the end of the commercials would be nice.
If wonder if Dr. Kenrick was sued into oblivion in the same way media lawyers went after ReplayTV for their “commercial advance” feature.
Radio “Commercial Killer” circuit schemes have been around almost since radio commercials. Most work by detecting the audio clipping in the signal. When the Audio signal ‘clips’ (exceeds the max amplitude of the circuit) the killer circuit shuts off the output. Generally there is like a three second delay before it can come back on.
Do radio stations still use tones to signal network and local breaks? Did they use them to automate at the time this article was written?
What is so interesting is the fact that back in the 1930′s, the line between content and commercials was so blurred. Think about how Arthur Godfrey, Lucille Ball, or any of those greats would transistion into live commercials. I wonder how that would have worked back then since there really wasn’t this hard delineation between content and commercials like there is today. I’m sure we would have seen product placement at an earlier time in broadcast history. Judy Garland’s Over The Rainbow might have had the line “way uppppp high…with Braniff Airlines”
M. Bruce Abbott
Creative Director/Partner
Radio Lounge
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