# Chapter 1

## 52 terms · Essentials of Audiology - Chapter 1

micro - µ

nano - n

pico - p

giga - G

tera - T

32 ft / sec²

energy

### What is the difference between mass & weight?

Mass doesn't change; weight is a byproduct of gravitational pull

kilogram / gram

### Metric units for displacement (d)

meter / centimeter

m/s & cm/s

v = d/t

a = v/t

F=Ma or =Mv/t

### Metric units for force (F)

Newton (N) & dyne

### Metric units for Pressure (p)

pascal (Pa) & microbar (µbar)

W=Fd

Joule & erg

watt

I=P/A

20 µPa

### Reference value for 0dB as measure of Intensity

10⁻¹² w/m² or 10⁻¹⁶ w/cm²

### condensation

air molecules forced together

### rarefaction

a part in a longitudinal wave where the particles are spread apart

...

a period

1/Frequency

### Hz is a measure of _____ that is measured in ____.

Frequency ... cycles/second

### The formula for wavelength is:

speed of sound / frequency = (343m/sec) / (cycles/sec)

### A 500 Hz tone has a period(cycle) of _____.

period = 1/freq. = 1/500 = 2msec

### wavelength is:

the distance between condensating air molecules

### Sound level meters measure dB SPL in _____ values.

Root mean squared (RMS)

### If 2 sounds are played 180 degrees out of phase, they do what?

cancel each other out

louder

### fundamental frequency

the lowest-frequency component of a complex periodic sound

1000 Hz

### white noise

a hissing sound that results from a combination of all frequencies of the sound spectrum

### pink noise

More energy at lower frequencies; decreases in amplitude at 3 dB per octave

### brown noise

Similar to Pink Noise with power density decrease of 6 dB per
octave with increasing frequency

### blue noise

noise restricted to the frequency ranges between 10,000 Hz and 22,000 Hz

logarithmic

### dB SPL =

20log (measured sound pressure / reference sound pressure)

### If the measured sound pressure is 1,000 times greater than the reference value, what is the dB SPL?

dBSPL = 20log1000 = 60

### If the measured sound pressure is 10 times smaller than the reference value, what is the dB SPL?

dBSPL = 20log(1/10) = -20dB

lower

80dB

lower

### inverse square law

as distance increases from the sound source, intensity decreases

### dosimiter

collects dB levels over time

### permissible exposure limit (PEL) is set by ______.

OSHA (U.S. dept of labor)

CDC

### octave frequencies

double or half of adjacent frequency (e.g. 125, 250, 500, 1000, 2000 etc..)