"stream from disc" WAV/AIFF file allocates tons of memory

Hi, can you please explain why a native AIFF/WAV file allocates more audio memory than its uncompressed file size?

That even happens when I use "stream from disc" option.

This memory issue is killing me and the release of my finished iOS app. I need the uncompressed file format in order to jump to specific sample positions (they increasingly shift if I use mp3)

Any help is much appreciated! Thanks!