Not only slow and fast sounds, but inner, audible and inaudible manifestations or translations of sound.

My recent vision I’d had, involving a ladder-like series of doors opening and closing silently. Felt sound.

Basically, the physical body has the potential for perceiving stimuli on a generalized basis. By this I mean that although the eyes are for seeing, the ears for hearing, and so forth. The potentials of the physical body include the capacity to hear, for example, through any given portion of the bodily expanse. Sound, then, can be felt as well as heard, although in such cases we may say that the sound is heard in the depths of the tissues; this, however, being an analogy. Feeling sound, merely experienced from a different perspective.