I play a .WAV trigger tone and have a JUCE iOS decoder app that catches it by processing the microphone data. It works perfectly on my iPhone 5. It is extremely robust.
Someone else is loading exactly the same code onto their iPhone6 and iPhoneX. They are playing the trigger tone from an identical MacBook Pro, but the decoder does not correctly recognise the tone.
The only explanation I can think of is that on these more modern devices there is maybe some preprocessing done on the microphone data, maybe some kind of echo-cancellation?
Does anyone know if this is true? And if so, is there any way to disable this preprocessing?