Acoustics

Question 1

What is a sound wave?

Answer 1

It is the vibration of air molecules around their resting state following a disruption of their surrounding state

Question 2

How does sound travel?

Answer 2

Sound travels in waves the areas of positive pressure are compression and the areas of negative pressure are rarefaction. Motion passes on through the molecules causing a wave of compression and rarefaction.

Question 3

What is a cycle?

Answer 3

It is one complete vibration made up of one compression and one rarefaction.

Question 4

What is period?

Answer 4

Time measured in seconds to complete one full cycle

Question 5

What is a wavelength?

Answer 5

Measure of distance between two identical parts of the wave. Peak to peak or trough to trough.

Question 6

What is frequency?

Answer 6

How many cycles occur per second measured in hertz

Question 7

Speed of sound calculation

Answer 7

V( speed of sound) divided by frequency = wavelength
Frequency x wavelength = v(speed of sound)

Question 8

What is a pure tone?

Answer 8

An audible tone that can be presented as a sine wave. Made up of only one frequency vibration with no overtones or harmonics.

Question 9

What is a complex sound

Answer 9

Most daily sounds. Made up of one or more frequencies. The lowest frequency is the fundamental frequency and any others are overtones

Question 10

What is a periodic sound?

Answer 10

Any sound that repeats a basic pattern. Usually a pure tone but an example of a complex periodic sound would be a sustained musical note

Question 11

What is an aperiodic sound

Answer 11

Any sound that does repeat a pattern. For example traffic noise has lots of high and low frequency’s.