Push To talk (PTT) with Arduino

Hi,
There are a number of applications that allow for PTT communications on smartphones running on Android and Apple OS.
As a project, I would like to create a PTT application using an Arduino to control a GSM modem and a simple 1 or 2 line LCD.
The audio side of things (mic and speaker) could either be controlled by the Arduino or the GSM modem.
I was wondering if anyone on the forum can point me in the right direction. I have had a fair amount of success using the Arduino to control a GSM modem for telemetry, but have never ventured into the arena of audio or PTT.
Any assistance would be greatly appreciated.

Set up a button and use variables to turn the microphone on or off

Do

int buttonState = 0;

at the start, before void setup() {

then use the "if" and "else" variables to turn the speakers on when the button is pressed
(something like)

if {
(buttonState == HIGH);
(then turn the microphone on)
}
else {
(turn microphone off)

Would it be with digitalWrite (microphone = LOW); or something?

correct me if I'm wrong, hope this helped

Hi ecoguy,
did it work for you? can you point me to the right direction?