In the process of hacking the rather cheaply made RS digital voice recorder I bought recently...
Remember the pic of the voice recorder I had in my April Fools entry ? It looked like the first pic below. It uses a cheap speaker for both speaker and mic. The sound from it is less then desirable, but not because of the chip used, but because costs were cut by using the speaker instead of a decent little Electret mic :-(
Well, I have started to work on changing this (as it was unusable as it was): I first soldered in a little mic from an old dictation machine (yeah, it used reel tapes) and this helped. But I wanted it to be more under my control, so I added a switch inline to the mic.
Now the sound is great, but it is still barely audible, so the next step is to make a 5X or 10X amp for the playback. I might even get ambitious and put a preamp inline with the mic.
This I have been working on in my "spare time" and also hope to get a CAKE (torte) entered into the contest on Monday.....busy busy busy :-)