Question

The human audible range of sound is from 20 Hz to ____ :

• A. 20 Hz
• B. 20 KHz
• C. 20 GHz
• D. 25 KHz

Hint:

The typical range of human hearing is:
{Lower limit:} 20 Hz (Hertz)
{Upper limit:} 20,000 Hz, which is equal to {20 KHz} (Kilohertz). Sounds below 20 Hz are infrasound. Sounds above 20 KHz are ultrasound.

Answer 1

The Correct Option is B

Concept: The human ear can perceive sound waves only within a specific range of frequencies. This range is known as the audible range or hearing range. Step 1: Defining the Audible Range For a healthy young human, the generally accepted audible range of frequencies is from approximately 20 Hertz (Hz) to 20,000 Hertz (Hz). Frequencies below 20 Hz are called infrasound, and frequencies above 20,000 Hz are called ultrasound. Step 2: Understanding Frequency Units
Hz = Hertz (cycles per second)
KHz = Kilohertz = 1,000 Hz
GHz = Gigahertz = 1,000,000,000 Hz So, 20,000 Hz can be written as \(20 \times 1000 \text{ Hz} = 20 \text{ KHz}\). Step 3: Identifying the upper limit of the audible range The lower limit is given as 20 Hz. The upper limit is 20,000 Hz, which is equivalent to 20 KHz. Step 4: Comparing with the options The question asks for the upper limit to complete the range "from 20 Hz to ___".
(1) 20 Hz: This would mean no range, which is incorrect.
(2) 20 KHz: This is equal to 20,000 Hz, which is the standard upper limit of human hearing.
(3) 20 GHz: This is \(20 \times 10^9 \text{ Hz}\), an extremely high frequency, far beyond human hearing (in the microwave range).
(4) 25 KHz: This is 25,000 Hz. While some individuals (especially young children) might hear slightly above 20 KHz, 20 KHz is the standard accepted upper limit for the general population. The most appropriate answer for the upper limit of the human audible range is 20 KHz.