Explain how sounds of different frequencies are detected in the cochlea.

Verified step by step guidance

1. The cochlea is a spiral-shaped organ in the inner ear that is responsible for converting sound waves into nerve impulses.
2. Sound waves enter the cochlea through the oval window, creating waves in the fluid-filled cochlear duct.
3. The cochlea is tonotopically organized, meaning different frequencies of sound waves stimulate different regions along the cochlear duct.
4. High-frequency sounds cause maximum vibration near the base of the cochlea, while low-frequency sounds peak near the apex.
5. Hair cells located along the basilar membrane are activated by these vibrations, converting mechanical energy into electrical signals that are sent to the brain via the auditory nerve.

Key Concepts

Cochlea Structure

The cochlea is a spiral-shaped, fluid-filled structure in the inner ear that plays a crucial role in hearing. It contains the basilar membrane, which varies in width and stiffness along its length, allowing it to respond differently to various sound frequencies. High-frequency sounds stimulate the base of the cochlea, while low-frequency sounds affect the apex, enabling the brain to interpret a wide range of pitches.

Frequency and Pitch

Frequency refers to the number of sound wave cycles per second, measured in hertz (Hz), and is directly related to the perceived pitch of a sound. Higher frequencies correspond to higher pitches, while lower frequencies correspond to lower pitches. The cochlea's ability to detect these frequencies is essential for distinguishing between different sounds in our environment.

Hair Cells and Signal Transduction

Hair cells are specialized sensory cells located on the basilar membrane within the cochlea. When sound waves cause the basilar membrane to vibrate, these hair cells bend, leading to the opening of ion channels and the generation of electrical signals. These signals are then transmitted to the auditory nerve, which carries the information to the brain for sound processing.