Final answer:
Different portions of the basilar membrane are sensitive to sounds of different frequencies. The base of the basilar membrane responds best to high frequencies, while the tip responds best to low frequencies. Hair cells located in different regions of the basilar membrane are activated by different frequencies, allowing for the perception of different pitches.
Step-by-step explanation:
The characteristic of individual parts on the basilar membrane in response to frequencies is that different portions of the basilar membrane are sensitive to sounds of different frequencies. The base of the basilar membrane responds best to high frequencies, while the tip of the basilar membrane responds best to low frequencies. This is known as the place theory of pitch perception.
For example, hair cells that are located in the base portion of the basilar membrane would be labeled as high-pitch receptors, while those in the tip of the basilar membrane would be labeled as low-pitch receptors. The mechanical properties of the basilar membrane, such as its thickness and tautness, change along its length, allowing for different regions of the membrane to vibrate according to the frequency of the sound waves. As the frequency of a sound changes, different hair cells are activated along the basilar membrane, allowing for the perception of different pitches.
The cochlea encodes auditory stimuli for frequencies between 20 and 20,000 Hz. Frequencies as low as 20 Hz are detected by hair cells at the apex of the cochlea, while higher frequencies in the range of 20 KHz are detected by hair cells at the base of the cochlea, close to the round and oval windows.