ios - Force Built-in Mic over bluetooth headset's mic? -

i use built-in mic on device input , bluetooth headset output. session category , must avaudiosessioncategoryplayandrecord. have tried using setpreferredinput: built-in mic switches output device's speakers.

i've seen this (specifically comments) mention it's possible.

you can use code

// create , set audio session  avaudiosession* audiosession = [avaudiosession sharedinstance];  [audiosession setdelegate:self];  [audiosession setcategory: avaudiosessioncategoryplayandrecord error: nil];  [audiosession setactive: yes error: nil];   // set bluetooth microphone input  uint32 allowbluetoothinput = 1;  osstatus stat = audiosessionsetproperty (                          kaudiosessionproperty_overridecategoryenablebluetoothinput,                          sizeof (allowbluetoothinput),                          &allowbluetoothinput                         );  nslog(@"status = %x", stat);    // problem if not 0  // check audio route  uint32 size = sizeof(cfstringref);  cfstringref route;  osstatus result = audiosessiongetproperty(kaudiosessionproperty_audioroute, &size, &route); nslog(@"route = %@", route);    // if bluetooth headset connected, should "headsetbt"  // if not connected, "receiverandmicrophone"  // now, play quick sound put in bundle (bomb.wav)  cfbundleref mainbundle = cfbundlegetmainbundle();  cfurlref        soundfileurlref;  systemsoundid   soundfileobject;  soundfileurlref  = cfbundlecopyresourceurl (mainbundle,cfstr ("bomb"),cfstr ("wav"),null);  audioservicescreatesystemsoundid (soundfileurlref,&soundfileobject);  audioservicesplaysystemsound (soundfileobject);