Too many AudioSources?

I'm not sure if this will work but,

Check out if there's any Rollof Factor in any of your sounds. They create a little distortion on your sounds (doppler effect). Hope this should solve.

Check out if there is any stereo sound. In this case, as you have a lot of small sounds, I'd recommend you to turn everything mono (there's an option... "Force to mono").

This two things should solve your problem... if it's about frequencies... if its all about the size of the files, try removing the samplers that already played and aren't meaningful anymore.

Destroy (game.getComponent(AudioSource));

this, maybe, can solve your problem.

Hope any of this possible solutions can fix this.