COMD 5070 Exam 3 (Latest 2023/ 2024 Update) Acoustics of Speech and Hearing| Questions and Verified Answers| 100% Correct| Grade A
COMD 5070 Exam 3 (Latest 2023/ 2024
Update) Acoustics of Speech and Hearing|
Questions and Verified Answers| 100%
Correct| Grade A
Q: How to calculate frequency? If there is a period of 2ms (0.002 seconds)?-
Answer:
1/0.002= 500 Hz.
Q: What is a harmonic series?
Answer:
When multiple sine waves or pure tones are combines together.
Q: What are integer multiples?
Answer:
The whole number multiples of whatever the fundamental frequency is.
Q: What is the fundamental frequency?
Answer:
The lowest frequency in a series that we will combine to make a harmonic series.
Q: How does sound transmit when the medium changes?
Answer:
-Sound will travel the most readily through a medium that is continuous, that does not change in
its properties from one place to another.
- Air is a medium.
- Air molecules oscillate with sound.
- Energy transmits through similar mediums.
- Change of medium will change if the sound is reflected or transmitted.
- Talking to a submerged swimmer: medium changed & now you have to speak up, more sound
is being reflected than transmitted. - Reflection can happen where tube size changes.
Q: How are decibels added?
Answer:
You always go up 6 dB when you add two identical intensities.
Q: What is 20 dB + 20 dB?
Answer:
26 dB.
Q: What is 50 dB + 50 dB?
Answer:
56 dB.
Q: What is an octave?
Answer:
A doubling of Hz.
Q: How many semitones are there per octave?
Answer:
12.
Q: What is happening when you go from 400 Hz to 800 Hz?
Answer:
Going up one octave.
Q: What happens when you go up and down octaves?
Answer:
The mathematical relationship between the frequency changes.
Q: Note pairs blend one of two ways. What are these two ways?
Answer:
- Harmonious- ly.
- Dissonantly.
Q: If there are 12 semitones between 100 Hz and 200 Hz, how many semitones would there be
between 500 Hz and 4000 Hz?
Answer: - You first have to determine how many octaves there are, then multiply by 12 to get the
semitones. - 36.
Q: What are the three things one should know about the 12 notes between octaves?
Answer: - Each step in nonlinear.
- Each step upward is bigger than the last (about 5.9% higher in frequency).
- No two semitones are identical; however, they sound equal in step size.
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What is the nature of science?
The scientific approach involves collecting data so that we can understand the given phenomenon from our own direct experience.
Science is empirical. What does that mean?
Based on data, collect data and interpret data.
Science is deterministic. What does that mean?
Obeys physical laws.
Science is predictive. What does that mean?
If you do this… then that will happen.
Science is parsimonious. What does that mean?
Uses the most straightforward explanation possible.
What is a transverse wave?
A wave that travels across the surface of a medium, such as water.
What is an example of a transverse wave?
- Pebbles in a pond cause circular ripples that would cause a toy boat in the water to bob up and down, the water itself doesn’t move, but the wave moves.
- A wave in a stadium.
What is a longitudinal wave?
A local change in tension, causing pressure compressions and rarefactions.
What is an example of a longitudinal wave?
A slinky.
How does sound transmit through air?
- Vibrations will travel through the air as the molecules move back & forth-air molecules move right left & right multiple times in a vibrating pattern.
- The molecule next to the item that made the sound is not the one going all the way into the ear.
- Molecules push/pull their neighboring air molecules.
- The vibration then travels, (because it’s carried on through the molecules) not the molecules themselves as they return back to their original home and vibrate around their home position.
Can sound travel through the vacuum of space?
No.
What is a period?
- In seconds is 1/frequency in Hz.
-The amount of time it takes for 1 full oscillation to occur (going from displacement away from resting position
beyond resting position to the negative side and back to rest).
-It is the opposite of frequency.
What is the frequency?
- In Hz is 1/period in seconds.
-How often the air molecules vibrate (how often they leave and return back home). - Measured in Hz. 1 Hz means
1 oscillation or 1 vibration per second.
How to calculate the period? If there is a 250 Hz sine wave, what is the period?
1/250= 0.004.
How to calculate frequency? If there is a period of 2ms (0.002 seconds)?
1/0.002= 500 Hz.
What is a harmonic series?
When multiple sine waves or pure tones are combines together.
What are integer multiples?
The whole number multiples of whatever the fundamental frequency is.
What is the fundamental frequency?
The lowest frequency in a series that we will combine to make a harmonic series.
How does sound transmit when the medium changes?
-Sound will travel the most readily through a medium that is continuous, that does not change in its properties from one place to another.
- Air is a medium.
- Air molecules oscillate with sound.
- Energy transmits through similar mediums.
- Change of medium will change if the sound is reflected or transmitted.
- Talking to a submerged swimmer: medium changed & now you have to speak up, more sound is being reflected than transmitted.
- Reflection can happen where tube size changes.
How are decibels added?
You always go up 6 dB when you add two identical intensities.
What is 20 dB + 20 dB?
26 dB.
What is 50 dB + 50 dB?
56 dB.
What is an octave?
A doubling of Hz.
How many semitones are there per octave?
12.
What is happening when you go from 400 Hz to 800 Hz?
Going up one octave.
What happens when you go up and down octaves?
The mathematical relationship between the frequency changes.
Note pairs blend one of two ways. What are these two ways?
- Harmoniously.
- Dissonantly.
If there are 12 semitones between 100 Hz and 200 Hz, how many semitones would there be between 500 Hz and 4000 Hz?
- You first have to determine how many octaves there are, then multiply by 12 to get the semitones.
- 36.
What are the three things one should know about the 12 notes between octaves?
- Each step in nonlinear.
- Each step upward is bigger than the last (about 5.9% higher in frequency).
- No two semitones are identical; however, they sound equal in step size.
If one octave has 12 semitones, how many does two octaves have? Three octaves?
- 24.
- 36.
If going from 50 Hz to 100 Hz is going up by one octave, what would two octaves be? Three?
- 100 Hz to 200 Hz.
- 200 Hz to 400 Hz.
What is aliasing?
When one sound is misrepresented as another.
What happens when you sample too slowly?
Aliasing, it inaccurately records the original signal and you will miss what happens between samples.
When aliasing happens, what happens to higher frequencies?
They will be improperly recorded as lower frequencies.
How do we prevent aliasing?
Filtering before digitizing.
What filter should be used to prevent aliasing?
- Nyquist frequency.
- Frequencies above this are deleted, so they cannot contaminate the recording.
- Most modern frequencies do this automatically.
What is a frequency domain display?
- X-axis is frequency, Y-axis is amplitude
- Spectrum display: line spectrum shows frequency components of a periodic wave.
- Has harmonics that are multiples of the fundamental.
- Sounds are split so you can hear them individually, there is no noise between the lines.
- Upper harmonics are weaker.
What is a benefit of using a frequency domain display?
It shows individual components and relative proportions of each component.
What is a time domain display?
- X-axis is time, Y-axis is amplitude.
- A waveform that represents sound directly.
- Air pressure changes over time.
- Periodic wave with multiple sine wave components.
- An audio signal where the voltage of digital increases and decreases in proportion to the sound pressure.
On a 3D spectrogram, how high does the frequency go relative to the sample rate?
- Nyquist frequency (which is twice the frequency of the highest frequency component).
If interested at looking at high frequency speech components on a spectrogram, you should do what?
At least double the sample rate, and give it a little more safety margin above that.
What is a high pass filter?
High frequencies pass through, low frequencies are held back.
What is a low pass filter?
Low frequencies pass through and high frequencies are held back.
What is a band pass filter?
Allows a band of frequencies to pass through, holds back both higher and lower frequencies.
What is a band reject filter?
Allows higher and lower frequencies to pass through, holds back a band of frequencies.
Who created the Fourier transform?
Joseph Fourier.
What is the Fourier transform?
A way to analyze and split complex sounds.
What are the ideas behind the Fourier transform?
- All periodic sounds are made of a combination of sine waves.
- These sine waves may vary in amplitude (how big they are), phase angle (where they are in cycle relative to each other), and frequency (there can be many frequencies present in sound).
What does the Fourier transform create?
A spectrum from a time domain waveform.
What is the FFT?
- Fast Fourier Transform
- Term used when applying the Fourier theorem.
What does the FFT do?
- Goes from a time domain waveform to a frequency domain display.
- Takes a complex waveform and breaks it into a spectrum that shows individual components.
What is the FFT good and bad at?
Reveals the source and harmonic energy but is bad at showing formant energy.
What is stroboscopy?
A flash of light that illuminates the vocal folds in a particular position, it is a slow-moving representation of glottal fold oscillation.
What happens with a stroboscopy?
It captures a variety of different positions from open to closed to resting position over successive cycles.
What does a stroboscopy rely on?
- Animation.
- Has 30 frames/ second.
- Has to sync to fundamental frequency.
What can be viewed in real time?
A stroboscopy.
What is vocal perturbation?
- When voice is perturbed away from perfectly periodic repetition.
- Includes jitter and shimmer.
What can vocal perturbation be caused by?
Neurologic factors, airflow turbulence, or pathological tissue change (swelling, nodules, or polyps).
What is jitter?
- Random changes cycle to cycle in FREQUENCY.
- Co-occurs with shimmer.
What is shimmer?
- Random changes cycle to cycle in AMPLITUDE.
- Co-occurs with jitter.
What sound does not change?
Vowels.
Why don’t vowels change?
If you produce a vowel, you should be able to sustain it as long as you have breath. If you don’t change the shape of your vocal tract, you’d say that sound is time-invariant. If you look at any point in time during that vowel prolongation that should last several seconds, it should look just like any other point in that time frame.
What is an ordinary vowel called and why?
- Monophthong.
- The clear, steady state that is maintained for a period of time.
What sound changes?
Diphthongs.
Why do diphthongs change?
Because it is a combination of two vowel sounds where the speaker’s tongue moves from one vowel position to
another while pronouncing the diphthong.
What is the source of speech?
Larynx.
What does changing the source of speech involve?
- Loudness.
- Pitch.
- Voice quality.
Low pressure to larynx creates…
A soft voice.
High pressure to larynx creates…
A loud voice.
What is alaryngeal speech?
- A change in source.
- Larynx used to be the source, but once removed, the source becomes the sphincter.
What is the filter of speech?
The vocal tract.
What does change of filter of speech involve?
- Any changes that occur that are not due to pitch, loudness, or quality.
- Example: Sound resonating because of how the tongue is being constricted.
What is F1?
The first formant and the lowest peak.
What is F2?
Frequency of the second formant
What are F1 and F2 good for?
Identifying vowels, even in synthetic speech.
What do higher formants do?
Contribute to the naturalness of the vowel sound.
What happens with F1 when the tongue height increases?
The vocal tract is lengthened, resulting in a lower F1.
What happens with F1 when the tongue height decreases?
The vocal tract shortens, leading to a higher fundamental frequency. Vowels produced here tend to have a higher pitch.
What happens to F2 when the tongue is farther back in the mouth?
The vowel has a relatively low frequency.
What happens to F2 when the tongue is farther forward in the mouth?
The vowel frequency is being increased.
What are the features of F1?
F1 frequency is a bit counterintuitive. It rises as the tongue and jaw are lowered. This is because the resonating space where F1 is created is behind the tongue base.
What should we know about the vowel quadrilateral for children?
- It is the largest.
- Spreads the furthest up and to the right.
- Their formant frequencies are higher.
What should we know about the vowel quadrilateral for women?
- It is medium sized.
What should we know about the vowel quadrilateral for men?
- It is the smallest.
- It is the lowest down and to the left.
- Their formant frequencies are the lowest because of their larger resonating frequencies in their vocal tracts.
What do men, women, and children all have?
A similar quadrilateral shape.
What is a vowel ellipse?
A reflection of how much variability there can be in the first and second formants as you produce the vowel in different contexts. The frequencies can vary around a certain range in the central or ideal target, but it’s an acceptable version of that vowel.
What vowels are commonly undershot?
Corner vowels such as /a/, /i/, /u/, and /ae/.
What is vowel neutralization?
When the vowel is undershot when the person is producing normal speech. The position of the tongue is a little closer to the neutral vowel /a/ in the middle of the vocal tract.
When does articulatory undershoot occur most?
When speech increases in rate.
What are men’s formants like?
Lower frequencies because of their larger vocal tracts.
What are children’s formants like?
Higher frequencies because of their smaller vocal tract.
What is a voicing bar?
An isolated dark bar in the lower frequency of a spectrogram indicating vocal fold vibration.
Where would you see a voicing bar?
When voicing starts before the release of the plosive.
In this case, the silent interval is not literally silent.
Where is the sound created in a stop burst frication?
Burst differs by the place of articulation each sound has its spectral characteristics which is why placement differs.
Where is aspiration seen?
Only in the context of a voiceless stop.
Where is the sound of aspiration created?
In the glottis.
Why is aspiration created?
The vocal folds begin to adduct, and as they are coming together the air between them creates turbulence, which then becomes turbulent at the glottis, which generates noise.
What is a stop gap?
- A typical duration for most speakers.
- Characterized by a lack of energy during the time the articulatory constriction is being formed.
- This is easily seen if the stop occurs between vowels.
What is the duration of a stop gap closure?
50-150 milliseconds.
What do consonant-vowel formant transitions tell the listener?
Place of articulation.
What is a short VOT (voice onset time) associated with?
Voiced sounds.
What is a long VOT (voice onset time) associated with?
Voiceless sounds.
What is the total voice onset time?
Duration of the burst and frication plus the duration of the aspiration.
What is prevoicing?
When voicing begins before the release of a stop consonant.
Is prevoicing typical in English?
No.
What is a released stop?
- The sound produced when a stop consonant is released.
- Example: “pop.”
What is an unreleased stop?
- The consonant sound that is formed by creating a cosure of blockage in the vocal tract, but the closure is not released with an audible burst of sound.
- Example: “stop.”
What is a semivowel/glide/approximant?
- When the tongue is gliding or moving from one articulatory configuration to another.
- Half vowel-like because the vocal tract is relatively open and there is phonation during production.
What vowel is /j/ most like?
/i/
What vowel is /w/ most like?
/u/
What has the longest frication duration out of a stop, affricate, and fricative?
Fricative.
What has the middle frication duration out of a stop, affricate, and fricative?
Affricate.
What has the shortest frication duration out of a stop, affricate, and fricative?
Stop.
What is linguistic prosody?
Pitch based, has a big influence on the voice.
What is affective prosody?
Emotional prosody.
Who was the most accurate in the study we discussed when it came to recognizing emotional tone in speech?
- The English Mother Language (EMT) polyglots had the highest scores.
- Possibly because they became effective listeners while learning a second language.
- Women across the groups were better.
What is forward or anticipatory coarticulation?
Anticipating upcoming sounds. An early sound is influenced by a later sound.
What is back rounding or retentive coarticulation?
When a later sound is influenced by an earlier one.
What is a theory?
A broader conceptual explanation based on many observations, an overarching view of how something happens.
What is a model?
A simulation used to explain or test.
What is a hypothesis?
Tentative prediction on a specific topic/ a type of prediction you can make under a given set of
circumstances.
What are the three speech subsystems?
- Respiratory system
- Laryngeal system
- Articulatory system
How do the speech subsystems coordinate in a voiced stop?
- The vocal folds come in close and vibrate.
- Articulators come together in the position that produces a certain sound.
- Air pressure bursts out while vocal cords vibrate, and the phoneme is audible.
How do the speech subsystems coordinate in a voiceless stop?
- The vocal folds do not vibrate.
- Articulators come together to produce a certain sound.
- Air pressure bursts out and releases a certain phoneme.
Is there any evidence to support motor program theories?
Yes, from reaction time studies.
What is the motor program theory?
Before we start making movements that are involved in speech, we have to prepare for them. We select the right movements and then we place them in the right order to create intelligible speech.
What are acoustic targets?
All that really matters is the sound that comes out and the pathway we take to getting that sound result doesn’t matter nearly as much as the result that it be perceptibly acceptable to a listener
for speech comprehension. In a previous discussion, we mentioned motor equivalence. That is the fact that you can accomplish the same perceptible result in a few different ways.
What are articulatory targets?
Specific movements made by the vocal tract are the goal of the system and that we work to make sure that these gestures, these tongue, lip, or jaw motions, are accurately produced. In theory, each of these motions is stored somewhere in the brain for retrieval and future use as we produce speech.
What are aerodynamic targets?
We have to accurately manage the pressure in the vocal tract by whatever means are necessary. Ultimately, if we have the right pressures and the right flows at the right time and in the
right context, then we can produce speech accurately. Maintaining pressure accurately depends on the
valves we have available to us in the speech production mechanism. These would include the larynx by
abducting and adducting more, the velopharyngeal port by being open or closed, or constrictions that we make with the tongue or the lips in the vocal tract further downstream.
Is there evidence that non-speech oral motor exercises help?
No. Because of a principle called exercise specificity. If you want to improve speech, you have to practice speech.
What are non-speech oral motor exercises?
Making the tongue move through a greater range of motion, sticking out of the mouth, wagging side to side, in hopes of improving the persons natural ability to speak.
Does the tongue stay still during stops or other sounds?
No, all articulators move dynamically through all sounds
What is open loop feedback?
Once the arrow leaves the bow, they have no more control, and the arrow follows the path that it will dynamically follow based on the force with which it was released and the direction it was sent off in.
What is closed loop feedback?
When we rely on incoming signals to guide our further actions. The adjustments we make will help us to correct and improve the results.
Is closed loop feedback possible when it comes to rapid production of syllables and phonemes?
No.
How does auditory feedback help infants?
Helps to learn an association between movements and the sounds that result from those movements.
How does auditory feedback help adults?
Used to maintain the quality of what we are doing.
How do perturbation studies work? How do people speak when a bite block is placed?
The lips and tongue adapt to the presence of the fixed jaw and adapt to the static perturbation.
What is identification in speech perception?
When the person simply has to report, either by saying back to the researcher or pressing a button or simply writing down the sound that they perceived. There are no right or wrong answers.
What is discrimination in speech perception?
The job of the listener is to determine whether two stimuli are the same or different. They can then be graded as correct or incorrect.
What is a pattern playback machine?
Sounds drawn graphically on a display, and then a device would convert those traces into sound. Sort of doing the opposite of what an acoustic analysis does.
What is the benefit of a pattern playback device?
That it allowed them to manipulate specific components of sound. They could make subtle adjustments and then see what the sounds were like that resulted from these minor adjustments that they were making.
What is the motor theory of speech perception?
- Speech is perceived by reference to how it is produced.
- Listeners access knowledge about how phonemes are articulated and use that info to perceive.
- The acoustic signal is received into the brain, the brain then determines the gestures that produce the signal and then comes up with the syllables and words
based on the movements.
What is the perceptual magnet affect?
- Acoustic variants close to the prototype are harder to distinguish from it, it pulls them to it.
- Vowels that are close acoustically to the ideal target tend to be perceptually very difficult to distinguish from it.
What is a phonetic memory?
- A lasting memory, it is gradually acquired over a lifetime because of the many
repetitions of sounds we hear in the language that surrounds us. We create a lasting memory of the
sounds we use to communicate. - Creates a long term sound template, the template of sounds is a compilation of sounds produced in
their ideal way.
What is the basic unit of speech control?
We do not know. Scientists cannot agree on whether we regulate speech a syllable, sound, or single movement at a time.
What are the acoustic features of a stressed word?
- Increased intensity
- Increased fundamental frequency
- Increased duration
Who came up with the H&H hypothesis?
Lindblom.
What the H&H hypothesis?
Hyper and Hypo articulatory effort depending on the circumstances.
What happens when we want to be clear with our articulation?
The segment durations increase, and we release our sounds.
When a phoneme is produced on its own, what happens?
It is long in duration.
When phonemes are produced together in a cluster what happens?
It decreases in duration, shorter than a single phoneme.
What are within category changes?
When the changes are made to the left or right of the category.
What are across category changes?
When changes occur in the very sensitive region known as the phoneme boundary.
When infants are 4, 5, or 6 months old what happens?
They are able to respond to non-native phonetic categories that their parents cannot respond to.
What is perceptual assimilation?
A theory that claims that adults perceive unfamiliar non-native phonemes in terms of articulatory similarities/dissimilarities to native phonemes.
What the McGurk effect?
Being able to see the way someone is articulating and producing sounds does affect what you think they are saying. Visual perception has a role in speech perception.