Acoustics final ch. 6 and 7
Card Set Information
Acoustics final ch. 6 and 7
What are fundamental frequency differences due to?
dimensions of the vocal folds
What are power differences in women's speech due to?
the amplitude of vibration (determined by the source)
How much more amplitude measure is there for men than women?
6 dB more
What are open quotient differences?
time the vocal folds are apart
What are closed quotient differences?
time vocal folds are together
What is spectral tilt/slope?
losing amplitude for the harmonics as we go up in frequency (women tend to have more shallow slope than men)
What are the biggest differences between men and women voices?
Do men or women tend to have larger open quotients?
Are there tracheal resonance differences between men and women?
Do men or women have greater harmonic spacing?
What happens because of greater harmonic spacing?
formant frequencies may be more difficult to estimate
changing the analysis bandwidth is often helpful
do this by changing the number of points in the FFT
Are H1 and H2 amplitudes stronger in men or women?
women's are 6 dB stronger
women lose 6 dB per octave, men lose 12 dB per octave in slope
What are harmonics?
integer multiples of the fundamental frequency
What is harmonic spacing?
harmonics are further spread apart for women
Why do infants have higher fundamental and formant frequencies?
smaller vocal tracts
What are the intonation pattern categories for infants?
What are phonation types for infant vocalizations?
Why do formant frequencies lower with age?
the changing length of the vocal tract
When does the most dramatic change in formant frequency occur?
stability from 4 to 24 months
lowering from 25 to 36 months
the shape as well as the length of the vocal tract changes
What is jitter?
timing of the vocal folds coming together gets messed up
What is shimmer?
the distance of the vocal folds traveling apart is not relatively the same
What is a perturbation?
a small change
Can you hear and perceive jitter or shimmer?
What happens if the harmonics-to-noise ratio is low?
more air than voice
little amplitude, vocal folds barely coming together
What are the fundamental frequency statistics?
standard deviation- most important
What are jitter, shimmer, harmonics-to-noise ratio, spectral tilt, and fundamental statistics measuring?
just the source (nothing else)
What does a breathy voice spectral tilt mean?
slope drops off quick
What is hypernasality?
velopharyngeal incompetence (can't control the velum)
increase in formant bandwidths
decrease in overall vowel energy (mucus)
introduction on nasal formant
rise in F1 and lowering of F2 and F3
presence of antiformants
What is nasality?
air is coming through the nose when it shouldn't be
What is dysarthria?
motor speech disorders due to neurological damage
speech is very unintelligible
What are characteristics of dysarthria?
articulatory adjustments are neglected
diminished acoustic contrasts
incomplete stop closures
generally, timing and sequencing are interrupted
What can spectrograms obtained across time show?
if therapy is succeeding, positive acoustic changes should be seen
if therapy is not succeeding, no changes will be observed
the spectrogram, however, must be properly interpreted
What does supra mean?
Where are phonemes written?
on the segmental line
we write above the segmental line about intensity, etc (suprasegmentals)
What is coarticulation?
speech sounds are not produced in isolation, but in context (syllable, words and phrases)
english is highly anticipatory
coarticulators are saving time
How do some individual sounds lose their distinctiveness?
nasal sounds can make vowels nasalized
rounded sounds can make sounds rounded that aren't normally
What are the two types of coarticulation?
What is anticipatory coarticulation?
features of a sound appear earlier than the sound
forward coarticulation (a sound effects the sound before it)
What is retentive coarticulation?
features of a sound carry over to the next one
backward coarticulation (a sound effects the sound after it)
usually has to do with nasality
What is temporal complexity?
phonemes become shorter when syllable length increases (if the word is short, we hold the vowel longer)
vowel duration gets shorter with more sounds before and after the vowel (trade-off between time and number of units within a word)
speech rate becomes a primary consideration
acoustic cues are not tightly bound to traditional phonemes
What is clear speech?
speech produced with an effort to be highly intelligble
contrast with conversational speech
broadcasters and air traffic controllers
we use clear speech for people with dysarthria (they need to overshoot to make their speech sound normal)
overarticulating can make it easier to be heard
What are characteristics of clear speech?
slower (durations longer for phonemes than expected)
avoidance of articulatory modifications
greater intensity of consonants (appears darker on a spectrogram)
Does clear speech affect an individual's intelligibility?
yes, but less natural sounding
How can clear speech make a person easier to understand?
greater fundamental frequency variability (greater variability in pitch when we articulate more)
precise timing (not rushing through the words, more equal timing for each word)
What is prosody?
melody of speech
not confined to phonemes
observed over much larger intervals
easier to pick up prosody if you have a larger sample of speech
What three acoustic features make up prosody?
fundamental frequency (observed as pitch)
intensity (perceived as loudness)
duration (perveived as length)
How is intonation included under prosody?
patterns of pitch rise and fall plus stress
content/meaning of message is changed
stress has more intesity and higher duration on a spectrogram
What is phrasal stress (emphasis)?
giving prominence to a word or phrase
contrastive stress (constrasts with previous info)
What are boundary cues?
mark the ends of language unites
changes in duration
adjustments of pitch
meter (rhythm)- pattern of stressed and unstressed syllables
Why is prosody not just a decoration?
gives us a lot of communication:
speech rate (pauses and vowels are shortened proprtionately more, stress patterns may also change)
vocal effort (adaptive adjustment to distance, not the same as loudness, neither is the same as intensity)
What is included under suprasegmentals?