The figure above shows a simple ic 741 based ultrasonic sound sensor alarm circuit.
Ultrasonic bat detector circuit.
Heterodyning and frequency division are real time methods i e.
These sounds lie in a frequency range above the human audible range and thus can t be heard directly.
Results can be displayed in real time with 30 second delay in either text or spectogram or bar chart format.
Firstly such transducers are very responsive to ultrasound and thus produce large output voltages upon detection as compared to a generic audio microphone.
The detecting device used here is an ordinary electret condenser mic.
Software is optimised for power saving and speed by using asynchronous classification.
The sound from the detector is heard at the same time the call is emitted by the bat.
This project is about building a so called bat detector i e.
Detection of the high frequency clicks bats emit must be done with an ultrasonic transducer for two reasons.
It has been suggested that bats utilize delay times arrival time differences and the doppler effect to interpret echoes.
As you probably know bats emit ultrasonic sounds for the purpose of echolocation.
The mic input is fed to the inverting input of the ic pin 2.
Heterodyning is the most sensitive method of the two but only transforms a small portion of the ultrasonic frequency range.
That s where the bat detector comes in.
A device that lets you listen to and record the sounds emitted by bats.