The place theory of hearing states that different parts of the cochlea are activated by different frequencies.
Learn more about the place theory of hearing and the structure of the ear.
What Is the Place Theory of Hearing?
The place theory of hearing is used to explain how we distinguish high-pitched sounds that possess a frequency that exceeds 5,000 hertz. According to the place theory of hearing, we can hear different pitches due to specific sound frequencies causing vibrations in specific parts on the basilar membrane of the cochlea. In other words, different parts of the cochlea are activated by different frequencies.Each location on the basilar membrane possesses a particular characteristic frequency. For example, a sound that measures 6,000 hertz would stimulate the spot along the basilar membrane that possesses a characteristic frequency of 6,000 hertz.
The brain detects the pitch based on the position of the hair cells that transmitted the neural signal.
Structure of the Ear
In order for us to truly understand the place theory of hearing, we must first have basic knowledge about the structure of the ear. This picture depicts the different parts of the human ear.
We absorb sound into the outer ear, which includes the external auditory canal and the auricle, or pinna.
The sound transforms into an acoustical signal after it is absorbed. The tympanic membrane, commonly known as the eardrum, is the part of the ear that separates the outer ear from the middle ear.Once the acoustical signal has reached the middle ear, the motion of the ossicular chain, which is made of the malleus, incus, and stapes, causes the acoustical signal to become mechanical.
The ossicular chain also carries the acoustical signal to the inner ear, the location where the sound enters the cochlea. This image contains the various structures of the cochlea. It also demonstrates how sounds of varying frequencies can activate specific areas of the cochlea.