Frecuency of Sound

Time ago, i was listening to a linguistic specialist, and he say in a moment althought i couldn't hear very well, that each idiom is spoken in differents frecuency of sound, so he say that for example spanish sound at 800 (?) and english at 1200 (?) This was one of the main reason for the problems when somebody without skill hear or spoke differents languages, problems of understanding and quick fatigue, because our cerebrum isn't accustomed to others frecuencies. Of course with time our cerebrums wouldn't have those problems but this require a true adaption to the other idioms.

What do you know about this?