Understanding the frequencies of sound waves is crucial in physics and acoustics. Sound is a form of energy that travels as waves. These waves are essentially vibrations that propagate through a medium, such as air, water, or solids. The pitch of a sound is determined by its frequency, which is the number of vibrations per second. Frequency is measured in Hertz (Hz), where 1 Hz equals one cycle per second. Kilohertz (kHz) is often used for higher frequencies, where 1 kHz is equal to 1000 Hz.

What is the Audible Range of Sound Frequencies?

The human ear is sensitive to a specific range of sound frequencies. Sounds with frequencies within this range are what we typically hear. This range is known as the audible frequency range or simply the audible range.

For a typical young, healthy human, the generally accepted range of frequencies that can be heard extends from a low frequency of about 20 Hertz ($\text{Hz}$) to a high frequency of about 20,000 Hertz ($\text{Hz}$). This upper limit can also be expressed as 20 kilohertz ($\text{kHz}$).

Sounds with frequencies below the audible range (less than 20 Hz) are called infrasound. Examples include seismic waves or vibrations from heavy machinery. Sounds with frequencies above the audible range (greater than 20 kHz) are called ultrasound. Examples include the sounds used in medical imaging or by bats for navigation.

Analyzing the Given Options for Audible Sound Frequencies

Let's look at the provided options concerning the range of frequencies of sound waves audible to human beings:

• Option 1: 16 kHz to 200 kHz
• Option 2: 16 Hz to 16 kHz
• Option 3: 20 Hz to 20 kHz
• Option 4: 14 Hz to 20 kHz

Comparing these options with the established audible range for humans:

• Option 1 (16 kHz to 200 kHz): This range is far too high. 16 kHz is within the upper part of the audible range, but 200 kHz is deep into the ultrasonic range, which humans cannot hear.
• Option 2 (16 Hz to 16 kHz): This range is close but not the standard accepted range. While some people, especially younger ones, might hear down to 16 Hz, the lower limit is generally given as 20 Hz. The upper limit is also usually cited as 20 kHz, not 16 kHz.
• Option 3 (20 Hz to 20 kHz): This range perfectly matches the widely accepted standard audible frequency range for young, healthy human beings. The lower limit is 20 Hz and the upper limit is 20 kHz (or 20,000 Hz).
• Option 4 (14 Hz to 20 kHz): This range includes frequencies below the commonly accepted lower limit of 20 Hz. While it covers the standard upper limit, the lower limit is typically stated as 20 Hz.

Based on the standard definition of the human audible range, the range from 20 Hz to 20 kHz is the most accurate representation among the given options.

Conclusion on Audible Frequency Range

The range of frequencies of sound waves audible to human beings is generally considered to be from 20 Hz to 20 kHz. This range can vary slightly from person to person and tends to decrease, especially the upper limit, with age.

Revision Table: Sound Wave Frequencies

Additional Information on Sound and Hearing

The human ability to hear sound involves several steps. Sound waves enter the ear canal and cause the eardrum to vibrate. These vibrations are transmitted through tiny bones in the middle ear to the cochlea in the inner ear. Inside the cochlea, fluid movement stimulates hair cells, which convert the mechanical vibrations into electrical signals. These signals are then sent to the brain via the auditory nerve, where they are interpreted as sound.

Factors affecting the perception of sound frequency and intensity include:

• Age: The ability to hear high frequencies typically diminishes with age, a condition known as presbycusis.
• Loudness (Intensity): The perceived loudness of a sound is related to the amplitude of the sound wave. Intensity is often measured in decibels (dB).
• Exposure to Noise: Prolonged exposure to loud noises can damage the hair cells in the cochlea, leading to permanent hearing loss.

While the 20 Hz to 20 kHz range is standard, sensitivity within this range is not uniform. Humans are typically most sensitive to frequencies between 1 kHz and 4 kHz, which corresponds to the frequencies of human speech.