![audio decibel convert to linear scale audiometer audio decibel convert to linear scale audiometer](https://thumbs.dreamstime.com/z/decibel-scale-sound-level-102089644.jpg)
If they are left free the gain will be set as 20 by default. The gain of this particular op-amp can be set from 20 to 200 using a resistor or capacitor across pin 1 and 8. We have already used this LM386 IC to build a low voltage audio amplifier Circuit and the circuit more or less remains the same. Do note that this project does not aim to measure dB accurately and will just give values as close as possible to the actual value.Ĭircuit for this Arduino Sound Level Meter is a very simple in which we have used the LM386 Audio amplifier circuit to amplify the signals from a condenser microphone and supply it to the Analog port of Arduino. To check if the values obtained are correct we can use the “Sound Meter” android application, if you have a better meter you can use that for calibration. We will use a normal amplifier circuit to amplify the sound signals and feed it to Arduino in which we will use regression method to calculate the sound signals in dB. So in this project we will use a normal Electret Condenser microphone with Arduino and try measuring the sound or noise pollution level in dB as close as possible to the actual value. And it is not economical to purchase expensive microphones for a small Arduino project which should measure the sound level in a small classroom or living room. Loudness or sound levels are commonly measured in decibel(dB), we have some instruments which could measure the sound signals in dB but these meters are slightly expensive and sadly we do not have an out of box sensor module to measure sound levels in decibels.
![audio decibel convert to linear scale audiometer audio decibel convert to linear scale audiometer](https://cdn.rekkerd.org/wp-content/uploads/2022/11/Process-Audio-Decibel-Spectrogram-update.jpg)
![audio decibel convert to linear scale audiometer audio decibel convert to linear scale audiometer](https://i5.walmartimages.com/asr/ed768b8c-f40f-4004-8cac-3e7c8a1c9f7a_1.c07a3e35a528c18dfd2572c48714fca7.jpeg)
A normal human ear could hear sound levels from 0dB to 140dB in which sound levels from 120dB to 140dB are considered to be noise. Noise pollution has really started to gain importance due to high population density.