I am working on a project where I am using a Arduino Nano to count number of Loud Sound (occurring at intervals) with intensity between 65 dB – 100 dB. I want to put a calibration unit and a digital display unit to calibrate the device within the aforesaid range and display the total count.
I am little bit concerned about the heart of the circuit – the sound sensor. I am thinking of a Electret Mic. Is it a good component to measure Loud Sound Level uniformly? I mean if I employ a electret mic to capture sound and place the output to an amplifier to measure the output analog signal, would it produce same analog reading (with minimum tolerance) for similar intensity of sound everytime? To further clarify it – when a sound is heard with 70dB intensity, if my arduino reads 95 from the sound sensor circuit, would it read something close to 95 everytime 75dB sound is produced?
Best Answer
It may be repeatable but not very accurate compared to B&K sound pressure monitor in an anechoic chamber.
Electret mics usually have an open back for far field cancellation,,so they are designed for near field sounds. They are not acoustically flat and thus may generate a poor comparison with different frequency sources.
But for your purpose for linearity, it may be ok, if you are not too loud or too close.