Physiology of Hearing

🌟 Cues:

• Physiologic anatomy of the ear
• Structure and function of external, middle, and inner ear
• Mechanism of hearing
• Auditory pathway
• Discrimination of sound
• Deafness types and tests

🗒️ Notes:

The ear is divided into three parts:

• External ear: Includes auricle and external auditory canal, responsible for collecting and directing sound waves.
• Middle ear: Contains the tympanic membrane and three ossicles (malleus, incus, stapes). Transfers sound from external ear to inner ear and amplifies sound waves.
• Inner ear: Cochlea and organ of Corti are the key structures. The cochlea transmits sound waves to the auditory cortex. The organ of Corti transforms mechanical vibrations into nerve impulses.

Hearing involves:

1. Transmission of sound waves to the inner ear.
2. Stimulation of the organ of Corti by sound waves.
3. Auditory pathway to the cortex.
4. Perception and interpretation of sound by the brain.

Deafness can be classified into:

• Conductive deafness: Due to problems in the external or middle ear.
• Perceptive deafness: Due to issues in the inner ear or auditory nerve.

📝 Summary:

The physiology of hearing involves the complex process of capturing sound waves and transmitting them through the external, middle, and inner ear. The ear not only amplifies these waves but also converts them into electrical signals that the brain can interpret. Deafness may occur if any part of this system is damaged, and it can be tested using tools such as tuning forks and audiometers.