How to get rid of glitch sound when start to play audio with BT Connected

Hi All,

I am working on VOIP application, I can clearly heared there is glitch when Starting audio session with Bluetooth connected, and happen on BT connected, HeadSet is fine.

[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord withOptions:AVAudioSessionCategoryOptionMixWithOthers error:nil];

[[AVAudioSession sharedInstance] setActive:YES error:nil];

Is there a way to get rid of this glitch?

App is registered to monitor Audio Routing changing event, and

It seems to occur when the there's a

AVAudioSessionRouteChangeReasonRouteConfigurationChange

AVAudioSessionRouteChangeReasonCategoryChange

Thanks,