Midterm Flashcards
period
time to complete one cycle
frequency
cycles per second (Hz.); inverse of period (smaller the time, higher the frequency)
frequency=
1/period (time)
human hearing threshold
20–20K Hz
pure tone propagation
compression and rarefaction periods
complex tone
2 or more pure tones of different frequencies, added in different ways
Fourier Analysis
decomposing waveform into sinusoidal components
time vs. amplitude plot; spectrum; spectrograph
time X, amp. Y (waveform); freq. X, amp. Y (glottal source); time X, freq. Y, amp. contrast
Sawtooth wave analysis
period waveform can only contain sines which are harmonically related to repetition frequency of original signal. Lowest freq. has to be period of original signal
harmonics
integer multiple tones of fundamental frequency: decrease in amplitude and increase in frequency
aperiod sound
random, no pattern; broad range of frequencies; also transient signals
resonance
frequency at which system vibrates most efficiently if set into motion by external force (res. freq. = natural freq. of a system)
examples of acoustic resonators
ported loudspeaker, string and wind instruments
things about decibels
base of 10 (log), use exponents to note (=bels); 2 60 dB sounds can’t be simply added together (between 0-66)
pressure measured in? (decibels)
micropascals; 20 mPa approximate threshold of hearing at 1K Hz.
best frequencies for human hearing
1-4K Hz
phon
equally loud contour compared to a dB SPL at 1K Hz
pitch measured in?
mels; 1000 mels = 1000 Hz.
Boyle’s Law
pressure + volume inversely related; increase in volume=decrease in pressure
expiration relies on:
torque of cartilage, gravity, elastic recoil
speech breathing
inspiratory muscles involved during expiration
myoelastic aerodynamic theory of phonation
elastic properties of VF and onset of vibration with air pressure from lungs; muscle activity (interarytenoids and lateral CA), sublottobal pressure buildup, muscle force, VF open bottom-top, air velocity increases through constriction, VF pressure decreases (Bernoulli), VF close bottom-top
Bernoulli effect
as air particle velocity increases, pressure exerted perpendicular to flow of particles decreases (ex: draft in corridor, leaves behind car)
intensity of vibration of VF falls at rate of?
12 dB per octave (frequency higher, intensity lower)
f0 (rate of vibration of VF) depends on:
tension, elasticity, mass
things about amplitude
increase muscle activity to increase resistance to air flow; increased amplitude without adjustment of muscle activity = higher f0
VF layers
epithelium, superficial l.p., intermediate, deep, vocalis
(cover-body theory) low pitch and amplitude=
weak contractions of CT + vocalis, slack body and cover
mid pitch and high amplitude=
weak CT, strong vocalis, slack cover, stiff body
jitter and shimmer
perturbation of frequency and amplitude (jitter values high at low amplitudes)
electroglottography
human tissue conducts electricity better than air, so pass weak current through each side of thyroid. Resistance to flow of current and resulting waveform (Lx) is direct measure of surface contact area of VF
Lx (glottal sound source) similar to sawtooth waveform
abrupt closure and less abrupt opening
formants and f0 vs. f1
resonant frequency of the vocal tract; F1= lowest resonant freq. (length of VT); f0=frequency at which VF vibrate
source filter theory
filter modifies source’s vibration by increasing energy at resonant frequencies (dependent on size, shape, degree of constriction)
F1 and F2 of front and back vowels
front vowels have wide F1 and F2 (and close F2 and F3), and back vowels have close F1 and F2 (and far F2 and F3)
vowel acoustic characteristics
frequency, duration, amplitude
vowel space
2-D or 3-d chart that plots F1 and F2 qualities of vowels, which relate to tongue height and advancement (if F1 on X and F2 on Y, then from top left clockwise we have i, ae, a, u)
ALS vowel space
collapsed vowel space; restricted tongue movement that probably wouldn’t reach the extreme edges of the vocal tract
Peterson and Barney vowel space
F1 going up, F2 going down
fragile X syndrom vowel space
imprecise, lots of variability
does increased pitch change the envelope of the spectrum (formants)?
no; filter has not changed
four aspects of vowel duration
phonological duration, postvocalic consonant effect, phrasal position, stress/emphasis (vowel duration can give you info. on vowel and next consonant)
tense vowel longer than lax vowels as long as
phrasal position, stress, postvocalic consonant, vowel height equal
acoustic definition of vowel
well-defined resonant frequencies that depend on the constriction (NOT physiology of vowel); openness of vowel tract leads to well defined resonant freq. (formants), which depend on the articulator constrictions; sound source is vibrating VF
octave
doubling of frequency
if amplitude is higher, then the spectral tilt
is less sharp, with more high frequency energy (only -6 dB per octave instead of -12)
nasal vowels
increase in formant bandwidth; decrease in overall energy; introduction of low-freq. res. freq. (nasal cavity); slight increase in F1 and decrease in F2 and F3
most open consonants are the
glides
diphthongs defined by
movement (not by single formant structure); dynamic sounds in which articulatory shape of VT changes slowly over course of production; described by onglide (starting formant value) + offglide
what happens to F2 after a laryngectomy?
it gets higher, maybe b/c vowels articulated with fronted and higher tongue positions relative to normal
consonant characteristics
more constriction in VT (= less intense, lower amp. sounds); period, aperiodic, or both
artic. continuum for stops-glides-diphthongs
stop (fast and total constriction); diphthong (slow and open VT); glide in between (main difference in openness and how dynamic; closed VT has less amplitude and high mouth pressure–high freq. filtered out?)
tongue up high =?
F2 up high
/r/ distinguishable by
large downward F3 transition
/j/ distinguishable by
sharply upward sloping F2 transition (high tongue position)
/l/ distinguishable by
slight downward F2 transition but no slope for F3 or F4 and side-branch in tube model (=anti-resonance as energy is lost into side branch; sudden dip in spectrum)
liquids and glides (characteristics)
well defined formants; dynamic (not one configuration of articulators); more constricted than vowels
perturbation if you have a cold?
mucous on one or both VF will increase density and lower frequency/irregular vibration; swelling of larynx also a factor
