here is what the manual says, I have never heard of memory seats having anything to do with audio settings
Driver Memory Seat
The driver memory seat buttons can store and recall three different driver’s seat positions as well as outside power mirror positions. Storing and recalling is possible with the ignition in the ON or STOP positions and the driver’s side door closed, or for three minutes after having opened the driver's side door. The performed position memory is confirmed by a beep. To set a memory profile, first adjust your seat (and power mirror position if desired) with the various controls until you are in the desired position. Then, push the specific button you want to assign the set position to for 1.5 seconds. When a new seat position is memorized, the previously memorized position on the same button is automatically overwritten. Recalling a memorized position is also possible for approximately three minutes after the doors are opened and approximately one minute after the engine is stopped. To recall a memorized position, push the relevant button briefly.