OPTICS 2nd quarter

What are sound waves?

produced by vibrating waves, consists of mechanical vibrations in air and other substances. needs medium to travel, and is a type of pressure wave.

What does human hearing vary from?

varies from: in Hertz: 20 hz - 20k hz, in Decibel: 0 dB - 120:130 dB

What is frequency (f) / pitch?

highness/lowness of sound. (Pitch) measured in hz

What is amplitude (A)?

loudness/softness of sound. measured in dB.

What is the speed (v) of sound?

how far the wave moves at 343 m/s in air.

What is wavelength (λ)?

inversely proportional to frequency.

What is timbre?

unique tone color that distinguishes one sound source from the other.

What role does a medium play?

needs medium to travel. more sound travel.

What does a high amplitude mean?

loud sound

What does a short wave length indicate?

(↑f, ↑pitch)

What does a long wave length indicate?

(↓f, ↓pitch)

What does a low amplitude mean?

soft sound

How many bels is 10 dB?

1 bel

What is 0 dB?

auditory threshold

What sound level is 20 dB?

whisper

What sound level is 60 dB?

normal conversation

What sound level is 80 dB?

shouting

What sound level is 120 dB?

uncomfortable

What sound level is 140 dB?

damage to cochlear reactions

When is a person said to have hearing loss?

a person is said to have hearing loss when his hearing is elevated to 20 dB or above.

What hearing severity is 0-20 dB?

normal hearing

What hearing severity is 20-40 dB?

moderate hearing loss

What hearing severity is 40-60 dB?

moderate severe hearing loss

What hearing severity is 60-80 dB?

severe hearing loss

What hearing severity is 80-100 dB?

profound hearing loss