Sound Transmission

1
Sound Transmission

• All sound is vibration

2
Sound

• Must have
• Sound Source

• Propagation Medium

• Receiver (???)

3
Vibration Pendulum

• Potential Energy
• Kinetic Energy
• Gravity, Resistance,etc.

4
Vibration Spring-Mass System

• Mass
• Elasticity (stiffness)
• Resistance (damping)

5
Sound Source
6
Propagation Medium
Particle Movement
A
B
C
D
E
F
G
7
Propagation Medium
Particle Movement
0
1
2
3
4
5
time
6
7
8
9
10
8
Sound Factoids

• Period (T)
• The amount of time required to complete one
  cycle
• T1/f and f1/T
• Speed of Sound (c)
• The distance sound travels over time
• c1100 ft/sec (340 m/sec)
• Wavelength (l)
• The distance traveled by a single cycle
• lc/f

9
Sound Factoids

• Longitudinal v. Transverse Waves
• Transverse direction of particle motion is
  perpendicular to direction of propagation
• Longitudinal direction of particle motion is
  parallel to direction of propagation

10
Graph Factoids

• Acoustic Information
• amplitude
• frequency
• phase
• duration

• Graphs
• waveform
• amplitude spectrum
• spectrogram