Hearing

  1. Sound Waves:

    • Created by vibrations that cause air pressure changes.

    • Consist of condensation (high pressure) and rarefaction (low pressure).

  2. Properties:

    • Amplitude: Determines loudness (height of wave).

    • Frequency: Determines pitch (wave cycles per second).

  3. Signal Transduction:

    • Sound waves are converted into electrical signals by hair cells in the cochlea.

    • Vibrations of the basilar membrane cause cilia on hair cells to bend, initiating signal transduction.

  4. Auditory Anatomy:

    • Outer Ear: Collects sound waves.

    • Middle Ear: Amplifies vibrations.

    • Inner Ear: Cochlea processes vibrations into electrical signals.

  5. Hearing Range:

    • Humans have a limited frequency range compared to other species (e.g., bats with echolocation).

  6. Cochlear Function:

    • The cochlear partition separates the scala vestibuli and scala tympani.

    • Hair cells in the organ of Corti are vital for hearing; damage can cause deafness.

  7. Frequency Representation:

    • Different regions of the basilar membrane are tuned to specific frequencies.