Physiology Prelab Lecture: Hearing

🌟 Cues

• Hearing assessment methods
• Tuning fork tests: Weber’s and Rinne’s
• Audiometry (PTA)
• Sound wave properties: Frequency & Amplitude
• Types of hearing loss: Conductive, Nerve, Mixed

🗒️ Notes

Tuning Fork Test: Detects the type of hearing loss (deafness).

Audiometry (PTA): Measures hearing by using sound waves at different frequencies and intensities. Human ear hears between 20-20,000 Hz, with human speech usually between 1000-3000 Hz. Intensity is measured in decibels (dB), and the ear hears within 0-140 dB.

Tuning Fork Tests

• Weber’s Test: Compares bone conduction in both ears. The tuning fork is placed on the center of the forehead. In normal cases, hearing is equal in both ears. Conductive deafness: better hearing in the diseased ear. Nerve deafness: better hearing in the normal ear.
• Rinne’s Test: Compares bone conduction and air conduction in the same ear. Tuning fork is placed on the mastoid bone, then near the ear. In normal hearing, air conduction is better. In conductive deafness: bone conduction is better. In nerve deafness: air conduction is better, but both are reduced.

Audiometry (Pure Tone Audiometry – PTA)

• Measures sound waves based on frequency (pitch) and amplitude (loudness).
• Used to detect hearing loss and determine if it is conductive, perceptive (nerve), or mixed.

📝 Summary

This lecture explains the physiological basis of hearing assessments, including tuning fork tests (Weber’s and Rinne’s) and audiometry. The focus is on how these tests detect different types of hearing loss—whether conductive, nerve-related, or mixed. Audiometry measures sound frequency and intensity to assess the degree and type of hearing impairment. Understanding these tests is essential for diagnosing hearing conditions.