The sample and hold module doesn’t produce sound. It is just used as a modulator. It contains a voltage input and a voltage output and a gate signal to control it. It produces a stepped voltage output from a variable voltage input. The output remains at the voltage that the input was when the gate signal was applied. So if a low frequency triangle wave was applied to the input and the gate was pulsed very quickly the voltage output would resemble something similar to steps going up and then steps going down.
White noise can also be used as a voltage input and then if the gate is pulsed again the voltage output would resemble random steps.