Does ITunes compress audios synced to iPhone

Question

I have a few mp3 320kbps audios I need to pass onto my iPhone, however I need the format to be exactly the same and I don’t want any compressing to be done to the audios. I wanted to know if when I sync the mp3 audios to my iPhone, will iTunes compress the audio or change the format in any way. Thanks to anyone who answers.

Answer 1

There's a switch in iTunes, under options, to either downsample or leave alone…

idk the equivalent in Catalina.

Speaking as a [retired] professional sound engineer, by the time you're listening on a phone, you may as well downsample to 128kbps AAC & save yourself some space, because you won't hear the difference.