I have an iphone SE (old version) that works perfectly except it makes a loud sound I can't hear, but the caller on the other end can. It makes the sound when I switch my phone to speakerphone each and every time, but also after several minutes on the phone with someone, and I haven't been able to figure out the stimulus for those occurrences. The sound reminds me of a short honk of a car horn or a buzzer, and is about 1/2 second in duration. Does the SE not like the latest iOS update, or is this a hardware issue. My friends complain it is REALLY LOUD if they are holding the phone up to their ear!!