Sound goes up every repeat

In the last level of my game m@r10 2.0 I have spikes come out of the ground on a repeat, every time it repeats the sound gets louder. Does anyone know how to fix this?

[Please leave the link to the game when asking about a problem or for help]

It could be overlaying from several inputs of the sound.
A number to the volume might help, but its more likely how the sound is activated


thx 4 the info