Physiology of hearing

Question 1

Range of human hearing

• Frequency
• Sound pressure level

Answer 1

Frequency

• 20 Hz- 20,000Hz
• Most sensitive to around 4000 Hz
• Human speech ranges around 100-10000Hz

Sound pressure
- Physical discomfort occurs around 100 dB.

Question 2

Middle ear mechanism of sound transduction

Answer 2

Main function- increases pressure to prevent reflection of sound in the cochlea

Tympanic membrane–> Oval window = increases pressure by 45x

Lever action of middle ear ossicles [malleus, incus, stapes]–> Increases pressure by 1.5x