PharEndEchoPhone

This is the evil twin of echo-cancellation that would allow you to induce callers who speak too fast to slow down and callers to whom you don't wish to speak at all to shut up.

This would function by taking the signal received from the far end, feeding it through a variable delay circuit, and transmitting it back to the far end.

I would like to see this implemented as a telephone or handset accessory with two controls, one to turn the echo on/off and the other to set the duration of the echo (5ms-2s?).

Previous posting have touched on this, eg: <see link>

I suppose this could be jury rigged and tested with a guitar echo/reverb pedal.