Turning off the sound in the game's options menu saves a very significant amount of time. Disabling the music mostly shortens load times, getting rid of the sound effects mainly reduces lag during the stages.

As we know so far, this is specific to the SNES version.

Sum of all load times

• ALL ON: 4:22.4
• MUSIC ON, SFX OFF: 4:22.4
• SFX ON, MUSIC OFF: 4:09.6 (-12.8s)
• ALL OFF: 4:08.5 (-13.9s)

Rough estimate of total lag reduction during stages with ALL OFF

• 1:20 to 1:25 (for a 1P1C run)