# Acoustics and Psychoacoustics - Chapter 2

## 27 terms

### Sinusoidal motion

Amplitude and wavelength

### Amplitude

Maximum distance that a point is displaced from its normal resting position (maximum displacement)

### Wave peak

Highest point of a wave

### Wave trough

Lowest point of a wave

### Peak-to-Peak Amplitude

Crest to trough; maximum displacement of the particles of a medium

### Energy

The amount of _______ carried by a wave is related to the amplitude of the wave.

### Equilibrium position

The "resting" position: no wave movement/disturbance

### Displacement

Distance that a point is moved from its normal non-vibrating position

### Wavelength

Distance from one point of a wave to the same point on the next adjacent wave

### Cycle

Time needed for a "complete round trip"' 360 degrees

### Period (T)

Time required to complete one cycle

### Frequency (f)

Number of cycles per second of time

### Phase

Point in the cycle of a waveform; measured as an angle, relative to the degrees of a circle

### Constructive interference

Addition of two waves when the crest of one overlaps the crest of another, so that their individual effects add together. The result is a wave of increased amplitude.

### Destructive inference

The crest of one wave overlaps the trough of another and the their idividual effect are reduced

### Beats

Two sounds with a small difference in frequency, moving slightly in and out of phase with each other, producing a pulsation of amplitude. DROP THE ______ !!!

### Velocity (v)

Rapidity or speed of motion; 1,100 ft/sec

f = 1/T

### Sound propagation and interference - 3 points

Absorb, continue, reflect

### Complex waves

May be impulsive and oscillatory (repeating) but are not pure tones

### Nonsinusoidal oscillatory waves

Sinusoidal waves that are related harmonically to one another

### Periodic complex waves

Amplitude vs. Time or Amplitude vs. Frequency

### Complex sounds

Have energy distributed at more than one frequency

Repeating

Non-repeating

### Fundamental frequency (F0)

Lowest frequency of a complex wave

### Harmonics

whole-number multiples of the F0