Auditory Theory: Acoustics

Lecture 002 Sound I

Reading Assignment for Lecture 003

Before next class please read section

• 1.2.n Sound Intensity power and pressure level

Pages 14 to 32 of Acoustics and Psychoacoustics.

Brain Bullets

• Newton:
  • Force which will change the velocity of a one kilogram (2.2 lbs) object by one metre per second over a period of one second.
  • Symbol: N
  • Units: kg sec per sec (kg ms^-2)

• Young's Modulus
  • A measure of stiffness or the force needed to compress a material
  • Symbol: E
  • Units: Newtons per square meter (Nm²⁾

• Pressure
  • Mass/area
  • Symbol: P
  • Units: kilograms per square meter (kg m^-2)

• Velocity
  • A measure of speed
  • Symbol: ν (nu) or c
  • Units: meters per second (ms^-1)

• Density
  • Mass per unit volume
  • Symbol: ρ (rho)
  • Units: Kilograms per cubic meter (kg m^-3)

• Cycle
  • One period of a wave oscillation

• Frequency
  • The number of cycles per second of a periodic wave
  • Symbol: f
  • Units: Hertz (Hz)

• Wavelength
  • The length of one cycle of a wave
  • Symbol: λ (lambda)
  • Units: meters (m)

• Impedence
  • Measure of resistance to the passage of sound
  • Symbol: Z
  • Units: Kilograms per sqare meter per second (kg m^-2 s^-1)