I use samsung omnia lite (model: GT-B7300) mobile phone. I always had issue with its mic. The person at the other side is not able to hear anything as well as there is break in voice.
I was able to setup for its optimum performance. And now it works great.
Here is how i was able to boost mic on Samsung Omnia Lite
Put this code *#0002*28346# Press Gain Go to Mic Amp Gain Set this: MGNR7 0110 MGNL3 1001 I hope it's will help you.