Acoustics Flashcards
Acoustics
the qualities and characteristics of sound waves
Acoustic Production
How sound is generated
Acoustic Propagation
How sound moves through and is affected by its environment
Acoustic Control
How sound can be prevented from entering or leaving space
Acoustic Interaction
What happens to sound energy when it encounters a boundary
Your perception in Acoustics
How sound is processed by your ear and brain
Direction Sound Energy moves from a Source
All directions
The Law of Conservation of Energy
total energy is neither increased nor decreased in any process
sound energy encounters a surface (3)
Reflection
Absorption
Transmission
Sound Energy Reflection
Energy sent back into a room
Sound Energy Absorption
Energy captured by a medium (converted into heat)
Sound Energy Transmission
Energy passing through a medium
Specular Reflections (2)
- bounce directly off a surface
- the incoming angle will equal the outgoing angle
Flutter Echoes
a series of reflections that continue to bounce back and forth between parallel hard surfaces
Characteristics of Reflected Energy
- wavelengths will react one way or another when reflected determined by the size, material, and mass of the boundaries of the space
echo
A “late” reflection
Reverberation
numerous, persistent reflections
True Reverberation
a phenomenon seen in larger rooms with many hard reflective surfaces
Absorption characteristic
The materials used in the construction play a part in the amount of sound energy absorption
porous absorber
- material of the absorber slows the molecules down
- there may still be some reflected sound while a much greater portion of the sound has otherwise been absorbed
Transmission characterisics (2)
- When sound is absorbed, it doesn’t just go away
- It may be converted to heat, or it may be transmitted through the absorbent material to an adjoining space
Ambient Noise
any sound other than the desired signal
Direct sound and reflected energy
you will always have the direct sound – the sound that arrives at the listener position in a direct, straight line from the source to the listener, and the reflected sound – the sound that takes any indirect path from the source to the listener
