06 - Phonation II Flashcards
Vocal Acoustics
Opening and closing of the vocal folds during phonation results in the generation of ____ (simple/complex) periodic sound with a certain _____ frequency
Generation of COMPLEX periodic sound with a certain FUNDAMENTAL frequency
Fundamental frequency can be measured directly from the speech _________
Waveform
What would an amplitude versus time display for /a/ show?
A complex periodic waveform
How do we measure the period of the /a/ waveform? (ie. where would we measure?)
Peak-to-peak measurement (duration of a single cycle)
Period is _______ (proportional/inversely related) to frequency
Inversely related
If we determined the period was 10 ms, what would be the frequency?
(1 cycle/10 ms) x (1000ms/second) = 100 Hz
Since hand calculations are very time consuming, especially when measuring F0 across several seconds of speech, what program(s) could we use instead?
Visipitch or other voice analysis programs
How do voice analysis programs measure pitch periods? Are they 100% accurate?
Algorithms may use peak detection or zero crossing methods, autocorrelation, or pattern matching procedures
No program or algorithm is 100% accurate (esp. with abnormal voices)
How can visualization of the pitch periods calculated by programs be useful?
To evaluate the accuracy of the automatic pitch tracking
How might we use selected hand calculations of the pitch in association with computer algorithms?
Can use hand calculations to verify the computer’s automatic results
What is Visipitch, and what is it useful for?
Visipitch is a commonly used pitch measurement system.
It is useful for continuous real-time display of pitch and intensity, and for rapid measures and auditory feedback training
What are 3 Fundamental Frequency (F0) Measures?
Average F0
Frequency variability
Maximum Phonational Frequency Range (MPFR)
What is another name for “Average Fundamental Frequency” and how do we find calculate it?
Also referred to as Speaking F0
F0 is averaged over the duration of a speech task or sample of connected speech
What two factors must we consider when assessing and interpreting F0?
Age and Gender Infants: 350-500 Hz Children: 270-300 Hz Young Women: 220 Hz Older Women: 180 Hz Older Men: 140 Hz Young Men: 120 Hz
What is the average F0 for Young Men? Are older men higher or lower? Older women?
120 Hz
Older men are higher
Young women are higher than older women, who are still higher than men
Name 3 things that may contribute to prosody (patterns of stress and intonation) and F0 variability?
Emotion
Stress or accent on syllables
Grammatical forms
How might F0 variability indicate a voice problem?
Too much or too little F0 variability may sound abnormal and indicate a voice problem
What does F0SD stand for?
F0 (Fundamental frequency) Standard Deviation
What does F0SD a measure of?
F0 variability
What is F0SD for normal conversation?
20-35 Hz
The difference between the highest and lowest F0 in a sample of connected speech is called______?
F0 Range
Which gender generally has a greater F0 Range?
Females:
Young male = 65 Hz
Young female = 95 Hz
Increases with old age
Infants have the greatest range (1200 Hz)
What does “monopitch” refer to?
Significantly reduced F0 range (associated with certain voice disorders)
During prolonged vowels /a/, the F0 and SDF0 should be very _____ (high/low)
Low: 3-6 Hz
Higher values indicate problems with pitch control
What doe MPFR refer to?
Maximum Phonational Frequency Range
MPFR is obtained while producing _______ or gliding tones
Stepping
The MPFR ranges from the ____ to the ______ tone that a person can sustain
Lowest to Highest
What is the average MPFR of adult males?
80-700 Hz (about a 600 Hz range)
Adult females: 135-1000 Hz (~850 Hz range)
Trained singers will have a wider range
Voice disorders associated with much narrower range
What is speech amplitude largely determined by?
The amplitude of sound that is created by phonation
*Speech and voice amplitude are roughly equivalent
What is speech/vocal amplitude measured in?
Decibels
Vocal amplitude must be referenced and calibrated using an accurate sound level meter placed ________
At a specified distance from the talker’s mouth (6-12 inches)
What two things is the average vocal amplitude level largely dependent on?
Speech activity Speaking context (eg. soft conversation, classroom, etc)
How is average vocal amplitude measured?
By taking the average value over the duration of a speech sample
What is the normal average conversation level in dB SPL?
68-70 dB SPL at 12 inches
Do age and gender have a large or small effect on average amplitude level?
Small effect
- children generally lower than adults
- women slightly less than men
- old=young
What are two ways we can determine the average amplitude level?
Measure amplitude by hand from the peaks in the speech waveform
Use computer programs (e.g. Visipitch) which give real-time continuous amplitude contours
_______ (reduced/increased) vocal amplitude can be an important indication of a voice disorder
Reduced
What are 3 measures of Vocal Amplitude or Intensity?
Average Amplitude Level
Amplitude Variability
Dynamic Range
Why might speech amplitude vary?
Emotions
Stress or accent on syllables
Grammatical forms
What are 2 measures of Speech Amplitude Variability?
SD of A (Standard Deviation of Amplitude)
Range of Amplitude
What is the normal SD of A value?
10 dB SPL
Voice disorders may show ____ (reduced/increased) range and SD of A
Reduced (monoloudness)
What does dynamic range refer to?
The softest phonation to maximum loudness of phonation (~50-115 dB SPL, which is a 65 dB range)
We might be concerned if the Dynamic Range is less than ____ dB in the mid range of F0
Less than 30 dB in the mid range of F0
What is the Voice Range Profile or Phonetogram? What should it show?
Dynamic amplitude plotted across F0 range
Should be wide in the mid range, but narrows at endpoints
-slight dip in range at point where we switch to falsetto (M:390 Hz, F: 440Hz)
What are cycle-to-cycle variations in F0 and Amplitude referred to as?
Frequency perturbation
Amplitude perturbation
What do frequency and amplitude perturbations estimate?
The average variation in each adjacent cycle of vocal fold vibration
What is the average cycle-to-cycle variation in the time (period) of vibration called?
Jitter
What does “shimmer” refer to?
The average cycle-to-cycle variation in the amplitude of vibration
What are normal jitter values?
<1% of F0
or <0.1 ms (expressed as absolute time)
What are normal shimmer values?
0.5 dB
“Signal to Noise Ratio” is also referred to as____?
Harmonics to Noise Ratio
What is the “Signal-to-Noise Ratio”?
The amplitude of the speech signal at the specific frequency of F0 divided by the amplitude of other non-F0 frequencies (excluding the harmonics)
When calculating the signal to noise ratio, the non-F0 frequencies are considered to be _____ (noise/signal)
Noise (i.e. like the frequencies produced during a whispered /a/ instead of a voiced /a/)
A normal voice will have a relatively _____(small/large) amplitude of noise frequencies relative to the F0 signal frequency
Small
Higher signal/noise (S/N) is associated with a _____ (poor/normal) voice
Normal
Lower signal/noise (S/N) is associated with a _____(poor/normal) voice
Poor
What are normal S/N values?
15-20 dB
Below 15 dB may indicate a voice problem
