Meee which part(s) of the ear changes sound to signals the brain can understand? outer ear inner ear middle ear and outer ear middle ear and inner ear

Middle ear and inner ear 

The answer is Middle ear and inner ear

Explanation:

The parts of the ear that are involved in changing the sound to signals that reach the brain are:

Middle ear = is a cavity located inside the petrosal portion of the temporal bone. It is one of the three parts of the ear and is located in the upper part of the cerebellum, between the brain masses and the eardrum. Inner ear = is the innermost part of the ear, formed by the cochlea, the organ of balance and the auditory nerve, formed by nerve fibers that transmit information between the cochlea of the inner ear and the brain.

This is what a calorimeter is used for simpler ex, to measure calories in food.