> > results of your experiment after you try it, i really want to know
> > if it works.
>
> Well, it does work sort of. Not very loud, the bandwidth is
> hopeless but you can understand what's being said. I recorded
> a song phrase off the nearest radio station - happened to be
> Chris De Burgh's "Lady In Red" (shudder) - on the ISD. Played
> back through an amplified speaker it's fairly reasonable quality
> and good volume. OK waveform etc. Far better than the ISD's
> squawky drive of course. Played back through a piezo, she not
> so good. Sweetening the recorded sound to a tight mid-range
> for voice would help, but volume is a problem. One option might
> be to try a 555's PWM configuration. I saw an application circuit
> in a magazine a long time ago using it this way and they claimed it
> was a passable "digital amplifier". I suspect the piezo would give
> you better volume with PWM rather than direct audio

I want to implement something similar to what you've done, record
and then play-back the sounds. From your experiment i get the picture,
the piezo is much better as an alarm than as a speaker.
I will try to use the ringing speaker from a cellular phone to see if
it is any good. Thank you for sharing your results :)
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