Sensor properly measure sound in decibel and also in frequency

Other Hardware Sensors
1

Hi.
i have a project which I have to measure sound in frequency and also in decibel units. do you have any recommendation of proper sensor to measure it?
thanks

2

You will need a microphone, an amplifier and an Arduino. Lots of Arduino sound level meter and frequency measurement (e.g. guitar tuning) projects are posted on line, so look through some of them.

To calibrate sound levels in dB, you will need a commercial sound level meter for comparison.

This will be a very challenging project for a beginner!

3

Hi Jremington
Thank you for your answer. i want to ask, how about using KY-038, do you recommend it to use that sensor for this project?
and as you said I will need a mic, amp, arduino as like this article?

Arduino Sound Level Meter - Measure Sound/Noise Level in dB with Microphone and Arduino (circuitdigest.com)

4

That article has the right basic idea, but makes a fundamental error that can destroy an Arduino. It applies amplified microphone voltages, both positive and negative, to the Arduino ADC input, which will destroy at least the input.

DO NOT follow the wiring instructions, and find a better article that applies a voltage bias, so that the ADC input is not destroyed.

Unfortunately, the half-dozen or so top hits to a web search I just did for "arduino sound level meter" make this same fundamental mistake.

This commercial circuit does it correctly:

5

thanks jremington.
thats great sound module. and then, do still have any recommendation besides that? or just that module properly measure sound in dB?
how about measure frequency of sound, do you have any ide?

6

how about the circuit in this article you think?

How to Use Microphones on the Arduino - Circuit Basics

is the circuit still not correct and has a mistake? (in the part " HOW TO CONNECT AN ELECTRET MICROPHONE AND PRE-AMP TO THE ARDUINO")

7

The KY-038 microphone modules do include a DC offset circuit that protects the analog input.

Use your multimeter to check the average voltage on the AOUT pin, which should be about 1/2 the supply voltage (Vdd or Vcc) with no sound present.

how about measure frequency of sound, do you have any ide

Search for "arduino audio frequency determination" or "audio spectrum analyzer". Most people use the FFT or autocorrelation methods.