Zusammenfassung der Ressource
Sound
Waves
- PROPERTIES
- loudness (amp) - loud and quiet
- pitch(frequency) - high and low
- quality (wave form/shape) - simple and complex
- ALWAYS LONGITUDINAL
- made of
- compressions
- Constructive
- high pressure
- speakers= pushed out
- rarefractions
- depression
- destructive
- low pressure
- speakers= pushed in
- FUNTIONS
- transmit energy through a medium
- go thru, around, and reflect off of things
- hav constructive and destructive interference
- similar to mechanical waves
- TUNING FORKS
- always vibrate at a
specific frequency
- OSILISCOPE
- PRESSURE/TIME GRAPH
- shows how pressure changes over a period of time
- Definition
- sound made by changes in pressure
- SOUND
INTENSITY
- measure of the amount of sound reaching an area (1m2) in 1 s
- exact measurement verses perception(loudness)
- pW/m2
- sound intensity level - to the power of 10
- measured in the Bel (B)
- or the decibel (dB)
- intensity increases by factor of 10 = increases by 1B
- conversions
- 1B = 10pW/m2
- VELOCITY OF SOUND IN AIR
- HUMAN HEARING
- 20 - 20 000 Hz range
- dogs - 50 - 50 000 Hz range
- infrasonic
- ultrasonic
- supersonic
- subsonic