Cat meow simulator circuit one

A nonlinear multivibrator is composed of transistors VTi and VTz, and its frequency is approximately
). 3Hz; the oscillation frequency of the oscillator composed of triode VT3 is about 800Hz. LM386 operational amplifier A is used as an audio
amplifier.
    The duration of the "mic" sound depends on the values ​​of the resistor Ri and the capacitor Cl; the interval time between two calls depends on the values ​​of the circuit
Rz and the capacitor Cz; the sound characteristics, the duration of the call and the weakening of the sound depend on the resistors R4, The values ​​of Rz and capacitor Ca
; the tone depends on the values ​​of resistor Rs-Ra and capacitor C4~C6.