It looks like you have not added the required frameworks AudioToolbox.framework AVFoundation.framework Security.framework or added the other linker flags -ObjC -Xlinker -lc++ you can find more info here https://www.sinch.com/docs/voice/ios/ solved IOS error about Sinch framework
The microphone can only be used by one process at a time. You can check if the Sinch video call is occupying the microphone using the snipped below public static boolean checkIfMicrophoneIsBusy(Context ctx){ AudioRecord audio = null; boolean ready = true; try{ int baseSampleRate = 44100; int channel = AudioFormat.CHANNEL_IN_MONO; int format = AudioFormat.ENCODING_PCM_16BIT; int … Read more