Acoustics and Sound Flashcards

What is the standard unit used to measure sound frequency?

Answer: Hertz (Hz)

Hertz (Hz) measures the number of complete sound wave cycles per second and is the universally accepted unit for sound frequency.

Compared to a 0 dB SPL reference, a 20 dB SPL sound is how many times more intense?

Answer: 100 times

The decibel scale is logarithmic; each 10 dB increase represents a tenfold increase in intensity, so 20 dB equals 100 times the intensity of the reference level.

Which frequency range is most critical for speech intelligibility?

Answer: 500–4,000 Hz

The 500–4,000 Hz range contains the most important frequencies for speech intelligibility, encompassing the primary energy of most vowels and consonants.

Approximately how fast does sound travel through air at 20°C (68°F)?

Answer: 343 meters per second

Sound travels at approximately 343 meters per second (about 1,125 feet per second) through air under standard room-temperature conditions.

Which of the following best describes a pure tone?

Answer: A single-frequency sinusoidal sound wave

A pure tone is a single-frequency, sinusoidal sound wave with no harmonics or overtones, analogous to the sound produced by a tuning fork.

What is the mathematical relationship between the frequency and wavelength of a sound wave?

Answer: Inversely proportional

Frequency and wavelength are inversely proportional; as frequency increases, wavelength decreases, governed by the formula: wavelength = speed of sound ÷ frequency.

What is the commonly cited threshold of pain for sound pressure level in humans?

Answer: 140 dB SPL

The threshold of pain is approximately 140 dB SPL, the level at which sound causes immediate discomfort or pain and can result in acute hearing damage.