when i recorded on ip6s+ and on ip7+, the one from ip6s+ does not have static sound during playback but will have it when playback the same video from ip7+. now i don't know if it's just playback issue.There are two types of hissing just to make it clear. The first one is a hissing caused by the cpu at the back of the appl logo which is perfectly fine. The second type of hissing appears in the playback of a video that we record in a quiet room. The second one definitely stays no matter which device I play the video in.
