Chapter 10.2, Problem 9R

To determine

To identify: the range of human hearing in decibels and the level of damage of the human ear.

Answer to Problem 9R

The range of human hearing is $0\text{dB-120}\text{dB}$ and the level of damage is above $85\text{dB}$ .

Explanation of Solution

Introduction:

The human hearing is specified for a particular band of frequencies and a particular range of intensities. Sound waves beyond this particular range cannot be heard by the human ear.

The human ear identifies frequencies between $20\text{Hz}$ to $20\text{kHz}$ . All sounds below $20\text{Hz}$ are known as infrasound. Similarly, all sounds above $20\text{kHz}$ are called ultrasound. The human ear has a range in decibels from $0\text{dB}$ to $120\text{dB}$ . Normally, frequencies above $85\text{dB}$ are dangerous to the human ear and above $120\text{dB}$ can cause permanent hearing loss.

Conclusion:

Hence, the range of human hearing in decibels is $0\text{dB}$ to $120\text{dB}$ and sound above $85\text{dB}$ for a prolonged period of time damages the ear.