Auditory, acoustic, acoustical mean of or relating to the hearing of sounds.
Auditory often stresses hearing more than sound.
Acoustic emphasizes sound with reference to its capacity for being heard or the conditions under which it is heard.
Both words are used in anatomy with little distinction, except that some human anatomists prefer acoustic.
Acoustical is often interchangeable with acoustic but when direct reference to the science of acoustics is intended, the former is preferred.