Chapter 8 and lateral /l/
F1 is related to...
F2 is related to...
F3 is related to...
F1 is related to tongue height
F2 is related to tongue advancement
F3 is related to lip rounding/configuration of the lips
Where is there resonance for a nasal murmur? Where is there antiresonance for a nasal murmur? Why?
For a nasal murmur, there is only resonance in the nasal cavity. This is because the velum is lowered, allowing air to flow through the nares. Nasal murmurs have antiresonance in the oral cavity and the sinus cavities/tubelettes. Acoustic energy is trapped in the oral cavity because it is closed off to the atmosphere, generating antiresonance.
Describe the source for fricative acoustics.
Air molecules move from high pressure (region behind the narrow constriction) to a region of low pressure (near the "exit" of the vocal tract/near the atmosphere). Fast-moving molecules shoot out of the narrow constriction's exit, generating turbulence or turbulent airflow. The resulting turbulent airflow creates an aperiodic sound.
True or false: stop burst spectra have different shapes based off of the stop's place of articulation.
True
Bilabial stops are diffuse-falling, alveolar stops are diffuse-rising, and velar stops are compact
What are the three spectral measurements used to quantify the spectra of fricatives?
1) Peak frequency: primary peak or frequency associated with the greatest amplitude
2) dynamic range: range of amplitudes between the highest and lowest energies along the smoothed curve (e.g., how flat or peaky is the spectrum)
3) Spectral moments: central tendency, dispersion, tilt, peakiness/kurtosis
Tongue height has a direct/inverse relationship with...
Tongue advancement has a direct/inverse relationship with...
Lip rounding impacts which formant the most and how?
Tongue height has a inverse relationship with F1
Tongue advancement has a direct relationship with F2
Lip rounding impacts F2 the most and has an inverse relationship with the other formants (i.e., as the lips are more round, the vocal tract extends, and the value of formants goes down)
Which nasal consonant will have the lowest antiresonance frequency? Which nasal consonant will have the highest antiresonance frequency? Why?
/m/ has the LOWEST antiresonance frequency and /ŋ/ has the HIGHEST antiresonance frequency. This is because /m/ has the largest back cavity of all the nasal consonants and /ŋ/ has the smallest back cavity of all the nasal consonants. Larger cavities yield lower frequencies, while smaller cavities yield higher frequencies.
What is the obstacle in the oral cavity that relates to fricative sounds? Fricatives with/without an obstacle have greater amplitude/intensity. Why is this?
For fricatives, the obstacle in the oral cavity is the teeth. Fricatives with an obstacle have greater amplitude because greater turbulence is generated when an extra obstacle is present, which generates a sound with greater amplitude.
Fricatives with obstacles: /s, z, ʃ, ʒ/
Fricatives without obstacles: /f, v, θ, ð/
What parts do all stop consonants have?
1) Closure Interval/Silent Interval
2) Burst/Stop release
3) Frication Interval
Affricates are a mixture of what two sound classes?
Fricatives and stops
What is the source for vowels? What is the filter?
The source is the periodic waveform generated by vocal fold vibration
The filter is the configuration of the vocal tract
What are the regions of resonance and antiresonance for nasalized vowels? How are nasalized vowels different from nasal murmurs and vowels?
Antiresonance is only found in the tubelettes/sinus cavities for nasalized vowels. Regions of resonance for nasalized vowels include both the oral and nasal cavities.
Nasal murmurs are different than nasalized vowels because the oral cavity is a region of antiresonance for nasal murmurs since acoustic energy is trapped behind a constriction.
Nasalized vowels are different from non-nasalized vowels since they are produced with a lowered velum, which allows for air to flow through the nasal cavity and oral cavity, creating oral and nasal resonances. Non-nasalized vowels have a raised velum and resonances are found in the oral cavity.
How is the source for voiced fricatives different than the source for voiceless fricatives?
The source of voiceless fricatives is the aperiodic turbulent flow events.
The source of voiced fricatives are the result of aperiodic turbulent flow events AND the periodic vibration of the vocal folds. Because voiced fricatives are produced with two types of sources, they are said to have a mixed source.
What is VOT and what does VOT stand for? What components of a stop are included in VOT?
VOT stands for voice onset time and looks at the time from the burst to the onset of voicing/the first glottal pulse of the following vowel.
In a voiced stop, VOT consists of the burst and the frication interval
In a voiceless stop, VOT consists of the burst, the frication interval, and the aspiration interval
What are the three important digital techniques for speech analysis?
1) sampling rate: the number of times per second the computer picks off a part of the waveform and stores it in a digital form (the number of samples per second)
2) filtering: a filter that eliminates all frequencies above one-half of the sampling rate
3) bits: the number of amplitude levels available for storing amplitude variations in an analog signal.
In vowel speech acoustics, are source and filter dependent on or independent of one another? Provide examples to support your answer.
Source and filter are independent of one another. Different speakers can produce the same vowel (different fundamental frequencies with the same vocal tract configuration), and the same speaker can produce different vowel (same fundamental frequencies with different vocal tract configurations)
What are the characteristics of the spectrum of a nasalized vowel?
F1 of the nasalized vowel has a lower amplitude than F1 of the non-nasalized vowel
The spectrum of a nasalized vowel has clear antiresonance
The spectrum of a nasalized vowel has a low-amplitude peak around 400 Hz
The back cavity of a fricative is associated with...
The front cavity of a fricative is associated with...
As the constriction in the front cavity gets smaller, what happens to the frequency?
As the constriction in the back cavity gets smaller, what happens to the frequency?
The back cavity is associated with antiresonance, while the front cavity is associated with resonance.
As the front cavity gets smaller, the resonant frequency increases. As the back cavity gets smaller, the antiresonance frequency increases. Regardless of whether the cavity relates to resonance or antiresonance, the frequency will always increase if the cavity size decreases.
How is the closure interval different between voiced and voiceless stops?
Voiceless stops have a completely silent closure interval, in which little to no acoustic energy is generated.
Voiced stops have evidence of weak periodic energy because the vocal folds vibrate during the closure interval.
What are the axes for a waveform, a spectrum, and a spectrogram?
Spectrum: x axis is frequency, y axis is amplitude
Spectrogram: x axis is time, y axis is frequency, z axis is amplitude
Where is the lateral /l/ produced? Where are the regions of resonance and antiresonance for lateral /l/ and which formant is most impacted by antiresonance?
Lateral /l/ is produced when the tongue tip (apex) touches the alveolar ridge. Air flows out of the sides of the tongue (region of resonance) and gets trapped in the area behind the tongue (region of antiresonance).
Nasal murmurs are greater/weaker in intensity than vowels. Why is this?
Nasal murmurs are weaker in intensity than vowels due to the presence of antiresonance and greater damping of nasal resonances.
Will /f/ or /s/ have a higher peak frequency? Why?
Will /f/ or /s/ have a greater amplitude? Why?
/f/ has a higher peak frequency than /s/ because the front cavity for /f/ is smaller for /f/ than for /s/. /f/ appears flat on a spectrum because the peak frequency is so high that it cannot be properly displayed (in essence, the frequency is so high it goes "off the page"). Larger cavities yield lower frequencies, and smaller cavities yield higher frequencies.
/s/ has greater amplitude than /f/. This is because /s/ has an additional obstacle, which generates additional turbulent airflow in the vocal tract.
Where is noise generated during the frication interval of a stop?
Where is noise generated during the aspiration interval of a stop?
Noise generated during the frication interval is generated in the vocal tract at or around a narrow constriction
Noise generated during the aspiration interval is generated at the glottis
What does linear predictive coding (LPC analysis)
LPC analysis looks at a simplified, smoothed spectra from a Fourier spectrum (containing all the details of the harmonics and their amplitudes). LPC analysis looks at the locations of the most prominent frequency components.