Good day!

I am trying to amplify my audio recordings using the LM386 module and an ECM microphone. The module is connected to a laptop's USB port using a USB power cable. The audio plug is connected to a mobile phone for recording purposes. Whenever I try to record, only static noises are present. When I adjust the VOL in the module, loud crack noises are recorded. What am I doing wrong? Thank you.

 

Where is your audio recording?
Where is the audio plug connected in the LM386 module?
What are you trying to record?
You will have to be clearer in your intentions. Do you have a sketch of what is connected to what?

 

Where is your audio recording? Here it is https://voca.ro/1e9MsDrfnOWF
Where is the audio plug connected in the LM386 module? The cables are stripped and connected to the board, the green (gnd) and orange (pos).
What are you trying to record? I'm trying to record a lung sound taken from the chest and back.
You will have to be clearer in your intentions. Do you have a sketch of what is connected to what? I'm sorry but here it is. I'm trying to make a low cost amplifier that will capture a lung sound and amplify it to be exported to a laptop.

 

The 386 is a 'power' amplifier. Your microphone probably needs a suitable pre-amplifier instead, or no amplifier at all.
Does the 386 module provide bias current to the ECM mic?
What frequency range do the lung sounds have?
Have you tried recording with the mic directly supplying a signal to the phone?

 

LM386 is meant for driving a loudspeaker, not the mic input of your phone.
As Alec says, you need to supply proper bias to the microphone for it to work.

 

Presuming that your phone has only a line level input, what you need is a microphone preamp, not a power amplifier line the LM386.

Also, your phone likely has a built in microphone. What are you hoping to achieve that the phone’s microphone does not do?

 

The 386 is a 'power' amplifier. Your microphone probably needs a suitable pre-amplifier instead, or no amplifier at all.
Does the 386 module provide bias current to the ECM mic?
What frequency range do the lung sounds have?
Have you tried recording with the mic directly supplying a signal to the phone?

What frequency range do the lung sounds have? The frequency range is from 20Hz - 4kHz.
Have you tried recording with the mic directly supplying a signal to the phone? No, Not yet.

LM386 is meant for driving a loudspeaker, not the mic input of your phone.
As Alec says, you need to supply proper bias to the microphone for it to work.

Thank you, Mr Chips.
If I use my laptop's mixed audio port, will it work?

Presuming that your phone has only a line level input, what you need is a microphone preamp, not a power amplifier line the LM386.

Also, your phone likely has a built in microphone. What are you hoping to achieve that the phone’s microphone does not do?

Thank you, BobTPH.
I am trying to make a lung sound recorder which has a coupling that can be attached to a chest or back of a person.

 

The LM386 module does not have a schematic to show if its mic input is for an electret mic and if it has a filter for the mic bias.
I guess its voltage gain is 100 to 200 and maybe you are feeding its output into the mic input of your laptop? Then the total voltage gain is way too high at 200 x 200= 40,000 times!

Try powering the mic amplifier module from a 9V battery.

 

Your phone is already capable of using an external electret microphone; that's how the earbuds with a mic on the cord work. https://www.epanorama.net/newepa/2014/09/15/android-device-external-mic-wiring/