1. Wavelength
Distance between two successive condensations or rarefactions.
Distance between successive identical points in the waveform. 1

2. Other terms
Pressure = Force/Area; Unit: Newton/meter2 , dyne/centimeter2 or Pascal (Pa)
Energy = Ability to do work; Unit: Joule
Power = Energy/Time; Unit: Joule/Second or watt 2

3. Sound intensity in terms of power
Amount of energy transmitted per second over an area of one square meter
Unit: watt/meter2 or w/m2 3

4. Normal human hearing in terms of power
Least amount of sound power that can be detected:
10-12 w/m2 or w/cm2
Sounds that are damaging to the ear:
102 w/m2 or 10-2 w/cm2 4

5. Bel and Decibel 1 Bel = 10 Decibels
Logarithmic units of sound intensity
Bel = log (I1/I0)
Decibel = one-tenth of a Bel, i.e.
1 Bel = 10 Decibels 5

6. Rules of exponents
Xn = X x X x X …….n times
X-n = 1/ Xn
X0 = 1 6

7. Laws of Exponents
Xa x Xb = X a+b
Xa/Xb = X a-b
( Xa)b = Xab 7

8. Logarithm
Question: To what power must a known base be raised to obtain a certain value?
2? = 8
23 = 8 is the same as
Log28 = 3 8

9. Laws of Logarithms log a * b = log a + log b log a/b = log a – log b
log (a)b = b * (log a)
log 1/a = - log a 9

10. log 10 = 1
log 2 =
log 3 = 0.48
log 7 = 0.85 10