The sentence is badly written, which is why it feels like a truism. But there is content in it.
> Sound, an omnipresent sensory stimulator, ...
Sounds are always being heard by your senses: ears + bass that you feel in your body.
> Sound ... continually engages our auditory and mental faculties.
The continuous usage of our senses then lets sounds force our brains to think in particular ways. This is distinct from above - brain vs ears.
> Sound ... holds significant relevance in the human experience ...
The continuous engagement results in sound being important to what being human means. Note that human experience is larger than what you think. So this is also distinct from above.