This API is available on Firefox OS for internal applications only.
The speakerEnabled property of the Telephony interface indicates whether or not the speakerphone functionality of the phone is enabled.
Syntax
// Is the speaker enabled? var speakerEnabled = myTelephony.speakerEnabled; // Turn on the speaker myTelephony.speakerEnabled = true;
Value
 A Boolean — true indicates the speaker is enabled; false indicates that it is not. You may read and write this value.
Examples
// Telephony object
var tel = navigator.mozTelephony;
// Receive a call
tel.onincoming = function (e) {
  var incomingCall = e.call;
  // Answer the call
  incomingCall.answer();
};
// Say we have a button that activates/deactivates the speaker phone
muteButton.onclick = function() {
  if(tel.speakerEnabled) {
    tel.speakerEnabled = false;
  } else {
    tel.speakerEnabled = true;
  }
}
Specifications
| Specification | Status | Comment | 
|---|---|---|
| Web Telephony | Draft | Draft | 
Browser compatibility
For obvious reasons, support is primarily expected on mobile browsers.
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari | 
|---|---|---|---|---|---|
| Basic support | No support | No support | No support | No support | No support | 
| Feature | Android | Firefox Mobile (Gecko) | Firefox OS (Gecko) | IE Mobile | Opera Mobile | Safari Mobile | 
|---|---|---|---|---|---|---|
| Basic support | No support | 12.0 (12.0) | 1.0.1 | No support | No support | No support |