Complex sound effects generator

This circuit uses four self-oscillating oscillators to produce a wide variety of complex sounds. Low-frequency oscillator IC3 regulates IC2, and IC2 regulates IC1. The sound produced by IC1 causes the frequency of IC4 to change. The transitions at different points turn IC3 on or off, the frequency of IC1 and IC2 is variable, and the frequency of IC4 is also variable. This circuit is not critical, so it can be adjusted to produce different sound effects.