Received numerous call fro 516-555-0187, New York, they never leave a message, I did answer this time and they asked about my computer - could hardly understand - told them I did not have any kind a a computer so why were they calling and then they hung up.
It could also damage the microphone in your cell phone if held too close to the phone.
Those are very tiny microphones and it would be expensive to try to repair an expensive smart phone.