Appendix A (Nature Of Sound) Flashcards
What us the nature of sound comprised of?
Acoustic energy being transmitted through a medium and perceived by a receiver in form of sound waves
What are sound waves?
Compression waves that are created by a physical vibration source and through the air to a receiver.
What are the five sound wave basic qualities?
Frequency, wavelength, amplitude, waveform, and phase.
What is high and low pressure called
High pressure crest
Low pressure trough
What is frequency
The number of times per second the cycle of the Soundwave repeats
What is frequency measured in
Hertz
What is the audible hertz range for humans
20hz to 20000hz
But most pitches are below 8000
What is wavelength
The physical distance covered by one complete cycle of a sound wave
What calculated wavelength
Speed of sound ÷ frequency
What is the speed of sound
Roughly 344m/sec at sea level and 60°
What is amplitude?
Energy in the soundwave.
The more energy creating the sound the greater the compression represented at the crest of the wave.
Whats related to what
Frequency is related to pitch
Amplitude is related to volume and dynamic
How is amplitude measured
From the 0 point to the top of the crest.
Measured in Decibels
What DB is the threshold of pain
130 DB
What is a waveform
The shape of the sound wave
What are most musical tone made up of
A prominent fundamental and many inaudible overtones
Which harmonic is the first
The fundamental
Which harmonics are out of tune
7th 11th 14th
What gives an instrument is timbre
Differences in intensity of harmonics
Why are lower intervals muddy
The dissonant harmonics are more audible than at a higher pitch
What is phase?
It measures how far in degrees a sound has traveled in its cycle
What else could phase be
The relationship between the similar waves
What is it called when two waves end their cycle together
Being in phase
Whats its called when two waves dont end their cycles together
Out of phase by ___ degrees
What is resonance
When the vibrations from one source are transferred to another object
What gives an instument its harmonics
Materiak shape and skill of musician
What is reflection
When a sound collides with an object and bounces off.
What does a soundwave lose during reflection
It loses amplitude due to absorbtion
What is reverberation
The sound you still hesr reflecting after the source has stopped transmitting
What are standing waves
Wave patterns formed from both constructive and desconstructive interference.
