What is the Tonotopic of the cochlea?

13.2. Tonotopy—the organization of sound frequencies along an axis—is evident in the basilar membrane of the cochlea and all brainstem and central auditory centers (reviewed in Appler and Goodrich, 2011).

What is place code theory?

The place code theory is given that name because it identifies each pitch with a particular place along the basilar membrane. It assumes that any excitation of that particular place gives rise to a specific pitch.

Who gave the place theory of hearing?

A theory of pitch perception first proposed in 1865 by the German physiologist, physicist, and mathematician Hermann Ludwig Ferdinand von Helmholtz (1821–94) according to which the perceived pitch of a tone depends on the position or place on the basilar membrane of the auditory receptors that transmit nerve impulses.

What is tonotopic arrangement?

In physiology, tonotopy (from Greek tono = frequency and topos = place) is the spatial arrangement of where sounds of different frequency are processed in the brain. Tones close to each other in terms of frequency are represented in topologically neighbouring regions in the brain.

What is tonotopic representation?

Definition. Tonotopic organization expresses gradients in the representation (maps) of sound properties. Such properties are frequency of tones, frequency ratios between harmonics and the pitch of complex sounds, speed and direction of frequency sweeps, sound intensity and location of sound in space.

What is difference between place theory and frequency theory of hearing?

The auditory nerve transfers these nerve impulses to the brain. Frequency theory of hearing can only account for sounds up to 5,000 hertz. The place theory of hearing accounts for sounds at or above 5,000 hertz.

What is meant by a Tonotopic map?

Tonotopic maps are a striking feature of the mammalian auditory cortex and underlie the representation of complex sounds, such as speech. This spatial separation of frequencies originates in the inner ear, where high frequencies are processed in the base of the cochlea and low frequencies in the apex.

Is place theory of frequency theory correct?

Place theory is accurate, except that receptive cells along the inner membrane lack independence in response. They vibrate together as suggested by the frequency theory. Sound waves travel along the membrane, peaking at a given region depending on the frequency.

What is wrong with the place theory?

The biggest problem of the place theory is that it fails to identify the pitch of a stimulus with missing fundamental. According to Helmholtz’s theory, it is impossible to perceive a pitch when there is no spectral peak at the position along the basilar membrane which corresponds to the frequency of the pitch.

What is the difference between frequency theory of hearing and place theory of hearing?

Where are tonotopic maps found?

Multiple tonotopic progressions can be found in various subdivisions of the auditory nuclei in the brainstem, midbrain, and thalamus, and in the auditory cortex of the cerebrum, as illustrated in Fig. 1 (Clopton et al., 1974, Ehret and Romand, 1997, Rees and Palmer, 2010).