exam 2 study guide Flashcards
Frequency
-number of times vibration occurs per second
-Hz or cps
Intensity
-degree or amplitude of particle displacement
-dB
Time
-time in which a cycle is complete
-seconds
Wavelength
-distance a wave travels in one cycle
Vocal Fundamental Frequency
-rate of vibration of vocal folds/ rate that they open and close
Wave composition of periodic sounds
-vibration occurs at a set rate and repeats
Wave composition of aperiodic sounds
-vibration does not have a repeated pattern; sound is a result of forcing air through constriction
Frequency characteristics of aperiodic sounds are affected by
Frequency is determined by:
-size and shape of opening
-texture of articulatory surfaces
-place of obstruction
Resonance
selective amplification and dampening of frequencies
results from reflection and concentration of sound waves in a cavity
Natural Resonating Frequency
frequencies close to NRF are amplified and those far away are damped
Harmonic analysis
complex periodic sound waves can be broken into sinusoids or simple sound waves (pure tone)
overall energy is not changed, just redistributed over different frequencies
Measurement of acoustic parameters
frequency
musical scale
made of octave, tones, and semitones
Orchestral standard scale
A4= 440
C0=16.35 Hz
Octave, Tones, Semitones
Octave is broken down into 6 tones
Tone is broken down into 12 semitones
Logarithmic scale with base of 2
ratio of one octave to the next is always two
100-200
500-1000
Formula of Number of Octaves
N(O)
N(O)=3.32*Log 10 of F1/F2
Formula for Number of tones
N(t)
N(t)=6octaves
N(t)=19.92Log 10 of F1/F2
Formula for number of semitones
N(st)
N(st)=12octaves
N(st)=39.84Log10 of F1/F2
Formula for Frequency Level of Octaves
FL(O)
FL(O)=3.32*Log10 of F/16.35
Formula for Frequency Level of Tones
FL(t)=19.92*Log10 of F/16.35
Formula for Frequency Level of Semitones
FL(st)=39.84*Log10 of F/16.35
Measurement of acoustic parameters- intensity
standard scale: Sound Pressure Level
.0002 dynes/cm^2 because it is the lowest that humans can hear
Bel
original unit of measurement
had logarithmic scale with base of 10 (1 Bel = a sound 10x greater)
Decibel
1/10th of a Bel
provides a definite scale