That circuit uses the MSM6322GSK which is only available in small 24 pin plastic SOP style package. A speech pitch converter IC that operates in real time and requires very few external components. It has a microphone preamplifier and line level input and the output requires only a single transistor to directly drive a loudspeaker. As well as the microphone preamplifier, the IC contains a 4th order low pass filter on input and a 3rd order low pass filter on output. In addition there is a build-in 8-bit A/D converter and 9-bit D/A converter.
The pitch of the speech is alterable in 17 steps over a range of one octave up and one octave down, and there are two models of operation. In the up/down mode two inputs are provided which when pulsed, move the pitch up or down sequentially through the pi