What are the two parts of the ear that gather and reinforce acoustical signals?

The correct choice identifies the pinna and external ear canal as the two parts of the ear that gather and reinforce acoustical signals. The pinna, also known as the auricle, functions as a funnel to collect sound waves from the surrounding environment. Its unique shape helps to enhance specific frequencies of sound, thus increasing the efficiency of sound wave capture.

Following this, the external ear canal acts as a passageway for the collected sound waves, directing them towards the tympanic membrane (eardrum). This configuration not only facilitates the gathering of incoming sounds but also contributes to amplifying those sounds before they reach the more sensitive structures of the inner ear. Therefore, together, the pinna and external ear canal play a crucial role in the initial stages of hearing by effectively capturing and reinforcing sound signals.