Hi Manoj Patil ,

if you need high-fidelity (16 bit resolution) you should use an external ADC plus a microcontroller.

If something between 8 and 12 bit resolution is sufficient you can use a microcontroller with integrated ADC. Since the only requirements in this case are an ADC and an asynchronous serial interface to connect to a Bluetooth module, you can choose from a host of 8-bit microcontrollers.

My personal preference would be a member of Microchip's PIC18 family because these provide Direct Memory Access (DMA) (a rare feature among 8-bit microcontrollers) which enables the internal transfer from the ADC to the serial interface to be achieved with little workload for the CPU.

Dear Manoj Patil ,

welcome!

Adding to prof. Jeorg one other important petameter is sampling rate which depends on the type of audio signal. If it is speech then the sampling rate is standardized at 8 ksamples/s.

As for the audio signal in the frequency range from 20Hz to 20kHz.

The standard sampling frequency is 44.1 kHz.

For any audio signal with a limited bandwidth BW, we can apply Nyquest sampling theorem.

fs>= 2 fs,

Normally fs is taken greater than 2 fax with fmax the maximum frequency in the audio signal. This is for easier interpolation by a law pass filter.

The other point is that in order to save storage capacity and transmission rate,

one may compress the signal with an MPEG standard such that MP3.

All this depends on the application.

Best wishes

Please read my book

Conference Paper The American University Laboratories For Electrical Engineering Part 2

I hope you find a good answer

One method is apply sound wave to A/D of a microcontroller and convert this analogue wave to digital data. you must get samples every some milisecond and save data on a array or other place. for getting best result you must use 12 bit A/D and increase speed of sampling. although number of optimum bit of A/D and sample rate is limited by sound wave quality and format.