Chapter 1

Question 1

What is sound?

Answer 1

• Auditory sensation

- can only occur when there is someone there and have the ability to hear

Question 2

What is a sound wave? And what is the study of sound waves called?

Answer 2

• “A disturbance in an elastic medium that propagates through the medium as a longitudianl wave motion”
• happens in the air
• study of sound waves is acoustics

Question 3

What do you need to create a sound wave? Give an example with voice

Answer 3

A force: something like gravity, striking, or plucking that acts on the vibrating body and causes it to vibrate
A vibrating body: receives the force and vibrates and causes the medium to vibrate
A medium: (also a vibrating body)

We exhale air (force) into and across our vocal folds (vibrating body) which cause it to vibrate. This vibration in turn sets air molecules in the air (medium) into vibration

Question 4

What are the characteristics of vibrating bodies? Explain

Answer 4

1. Mass and Length
   - mass: the quantity of matter present
2. Density
   - amount of mass per unit volume
3. Elasticity
   - enables recovery from distortion to either shape or volume
   Words associated with Elasticity
   - Tension- action of stretching or condition of being stretched
   -Stiff (tense)- not easily bent or displaces out of shape
   - Compliant- easily bent or displaced out of shape

Question 5

What are the characteristics of mediums? Name one medium

Answer 5

1. Mass
2. Density
3. Elasticity
   Air is a medium

Question 6

What is a simple harmonic motion? Is it common? What is it influenced by? what is Low damp vibrating bodies vs high damped vibrating bodies?

Answer 6

A simple vibration like a tuning fork and it is not common.
It is influenced by
1. inertia
2. elasticity
3. Friction (resistance) and gravity
- reduces the amplitude of displacement until it stops (damping)
-Low-damped VB slowly come to a stop
- High-damped VB stop more abruptly

Question 7

What is a Cycle?

Answer 7

maximum displacement in one direction reversing and passing the midline and reaching max displacement in the other direction and then reversing and passing midline again

Question 8

What is energy?

Answer 8

Something that can produce a change in matter/capacity to do work
Potential is max at max displacement
Kinetic energy is max at equilibrium

Question 9

What are the characteristics of vibration?

Answer 9

Amplitude-distance displaced
- the psychological attribute is loudness
- force affects amplitude
Period- how long it takes to complete a cycle
- mass, density, length, and elasticity dictates its preferred period
Frequency- the number of cycles that occur in 1000ms- the shorter the period the more cycles will occur
Psychological attributes of period and frequency
- Higher the frequency (shorter the period) the higher the pitch
- low mass and high elasticity
- the lower the frequency (longer periods) the lower the pitch
-high mass low elasticity