Vowels
What is comparative acoustic phonetics?
Why are nasal murmurs less intense than surrounding vowels?
Nasal murmurs have antiresonance (in the oral cavity and sinus cavities), resulting in greater absorption of sound energy
Why are semivowels grouped together?
Semivowels are grouped together due to their shared aspect of production
Which fricatives have flatter spectra and which fricatives have peakier spectra? Why?
The dental and interdental fricatives have flatter spectra and the alveolar and palatal fricatives have peakier spectra. The fricatives that are more front in the vocal tract are flatter because their peak frequency is so high that it cannot be quantified by the spectrum, so these spectra have a relatively flat appearance. Fricatives that are produced further back in the vocal tract have a peakier spectra because larger cavities yield lower resonant frequencies.
What is across-speaker variability?
What is within-speaker variability?
Across-speaker variability includes factors such as gender, dialect, language, and age. These are factors that we compare between two or more different speakers.
Within-speaker variability includes speaking rate, syllable stress, speaking style, and phonetic context. These are factors that we compare within the same speaker, but in different speaking contexts.
Explain the difference between a "slice-in-time" measurement and formant trajectories. Which one(s) can be used with vowels and which one(s) can be used with diphthongs and why?
A "slice-in-time" measurement only looks at one given point of time on a spectrogram, whereas a formant trajectory looks at the movement of formant patterns across the duration of the vowel.
A "slice-in-time" measurement and formant trajectories can be used with vowels because vowels experience little formant movement, meaning that they can be appropriately quantified at the temporal midpoint. However, because formant trajectory looks at the entire vowel duration, this would also be appropriate for a standard vowel sound as well.
Only formant trajectories are appropriate for diphthongs. Diphthongs are not just a combination of two vowel sounds, but are their own unique sound class. Because of this, it is unreasonable to look at the temporal midpoint of a diphthong because it will not appropriately capture the characteristics of the sound, since diphthongs are characterized by formant movement. However, because formant movement is integral to formant trajectories, one can use a formant trajectory to examine a diphthong sound.
What is nasalance and how do we measure it?
Nasalance is a measure of the acoustic energy radiating from the nares divided by the total energy emitted by the nares and the mouth.
Nasalance is obtained from an instrument called a nasometer.
Describe the constriction for semivowels. How does the semivowel constriction compare to that of obstruents (i.e. fricatives, stops, and affricates) and vowels?
Vocal tract constriction is tighter than that of vowels, but is not as tight as for obstruents
What is peak frequency and how does it change as the place of articulation moves backward in the vocal tract?
The peak frequency is the frequency in the maximum amplitude. Peaks decrease in frequency as the place of articulation moves backward in the vocal tract because larger resonators yield lower resonant frequencies.
What is articulatory undershoot and in what speaking contexts would it occur?
Articulatory undershoot occurs when the speaker aims for the idealized target, but misses it in connected speech because the articulators do not have sufficient time to reach the acoustic target before transitioning to the target for the next sound.
Articulatory undershoot occurs as a result of: phonetic context, increased speaking rate, reduced stress, and a casual speaking rate
What is null context and why do we use it?
/ə’hVd/
Null context allows for minimal influence from the surrounding phonetic context, and when a vowel is produced in null context, there are little or no coarticulatory effects from the surrounding consonants.
Regions of resonance and antiresonance for nasal murmurs and nasalized vowels
Nasal Murmur:
Resonance: nasal cavity; Antiresonance: oral cavity and sinus cavities
Nasalized vowels:
Resonance: nasal cavity and oral cavity; Antiresonance: sinus cavities
Rapid transitions into and out of the constriction interval during the production of a relatively short semivowel sound suggests what about semivowels?
Semivowels are comprised of very rapid, complex articulatory gestures occurring in a short amount of time
What are spectral moments and what do we use them for?
Spectral moments are used to quantify the shape of a fricative spectrum.
Spectral moments include mean, variance, skewness, and kurtosis
What are intrinsic and extrinsic vowel duration?
Intrinsic vowel duration relates to articulation of the vowel segment itself, as opposed to an external influence.
Extrinsic vowel duration relates to external factors that affect vowel durations.
What is vowel acoustic space and how is it measured?
How does vocal tract size impact the vowel acoustic space?
Vowel acoustic space relates to how a speaker positions their tongue in the mouth to produce each vowel sound.
Vowel acoustic space is created by measuring the F1 and F2 values of the target vowels and then plotting those values on a graph.
A larger vocal tract generally means a smaller vowel acoustic space, whereas a smaller vocal tract generally means a larger vowel acoustic space
What is A1-P1? How does the A1-P1 change between nasalized vowels and non-nasalized vowels?
A1-P1 is the amplitude of the first harmonic minus amplitude of the second harmonic
A1-P1 is smaller for nasalized vowels than non-nasalized vowels due to the presence of antiresonance
Is an error /w/ the same acoustically as a correct /w/? If a child can make a perceptual distinction between the sound they produce in error (e.g. /r/) and the sound they produce correctly (e.g. /w/), what does this mean?
An error /w/ is not acoustically similar to a correct /w/. If a child can make a perceptual distinction between the sound they produce in error and the sound they produce correctly, this means that the child is likely to self-correct the error later on and is more likely to produce the distinction more clearly than a child that cannot hear the perceptual distinction.
Why do sibilants have greater intensity than non-sibilants?
Sibilants have more intensity than nonsibilants because there is an additional obstacle in the vocal tract (i.e., the teeth), which generates more turbulent airflow, thus increasing amplitude.
Phrase-final/utterance-final lengthening relates to how vowels in the final position of a phrase or utterance are longer than other vowels in other parts of the phrase or utterance.
What impacts fundamental frequency?
What impacts formant frequency?
Does fundamental frequency impact formant frequency? Why or why not?
Fundamental frequency is impacted by the rate of vocal fold vibration
Formant frequency is impacted by the shape/configuration of the vocal tract
Fundamental frequency does not impact formant frequency. The source (vocal fold vibration) does not impact the filter (the vocal tract). For example, a single speaker can say different vowel sounds with the same fundamental frequency, and different speakers (with different fundamental frequencies) can produce the same vowel (with the same vocal tract configuration).
What parts are used in determining a nasal's place of articulation?
Murmur piece, Murmur and Transition piece, and Transition piece
Are semivowel errors common during phonological development and in speech delay? Why or why not?
Semivowel errors are common during phonological development and in speech delay. This is because semivowels have unique and shared gesture characteristics, complex vocal tract configurations, and involve rapid articulatory movements to and away from a narrow, vocalic constriction
Why are sibilants longer in duration than nonsibilants?
The turbulent source is not only stronger but is active over a longer period of time for sibilants than nonsibilants
F0: fundamental frequency
F1: tongue height
F2: tongue advancement