Quiz 2/Final: General Flashcards
Sharply versus Broadly tuned resonators
- Sharp Tuning:
- system responds to a small range of frequencies
- vibration persists for a long time (low damping)
- examples: tuning fork, crystal glass
- Broad Tuning:
- system responds to a larger range of frequencies
- vibration dies out quickly (heavy damping)
- examples: sound in air, phone earpiece
What are the two types of sound source?
- A: phonatory/subglottal source: vibration of vocal folds at the glottis, periodic (AKA vowels)
- B: supraglottal source: air passes through larynx to upper vocal tract (mouth) where airstream is modified, aperiodic (aka unvoiced consonants)
How do source and filter relate?
-whether the source is subglottal (glottis) or supraglottal (mouth), the sound is filtered by the resonant frequencies of the vocal tract
Source and filter: specifics in voiced speech
- At any given time in the production of a vowel, the spectrum of the sound radiated from the lips can be found from the product of
- the excitation (source) spectrum generated by the larynx
- the frequency response (filter) of the vocal tract configuration
- In voiced speech:
- fundamental frequency (perceived as vocal pitch) is a characteristic of the glottal source
- features such as vowel formants are characteristic of the vocal tract filter (resonances)
- Any change of vocal tract configuration alters the frequencies at which the cavities resonate
- Size and length of the vocal tract also alters the frequencies at which the cavities resonate
Source and filter: Independence of source and filter, clinical populations
- you hold the source constant while changing the filter to:
- maintain constant pitch (f0)
- vary vowel (eg change from [i] to [u])
- you hold the filter constant while changing the source to:
- articulate a single vowel (eg [i] in isolation)
- vary f0 (eg from low to high pitch)
- How does this relate to clinical populations:
- a client’s speech disorder can often be isolated to the source or the filter
-Any vowel sound produced is a product of vocal fold vibration (the source) and the resonances of a particular vocal tract shape and length (the filter)
Acoustic Resonators Relative to Speech and Hearing:
- Vocal Tract:
- both air filled and closed at one end
- the closed end of the vocal tract is the vocal folds for voiced sounds
- Ear Canal:
- the closed end is the eardrum
Resonating Cavities of the Vocal Tract
- all of the air cavities above the larynx from the glottis to the lips
- Large resonating cavities: pharyngeal, oral, and nasal cavities
- Small resonating cavities: air spaces between the lips, between cheeks and teeth, and within the larynx and trachea
What factors are involved in the resonation of air filled tubes? (4 things)
- Air filled tubes resonate at specific frequencies depending on:
- 1: whether it is open at one or both ends
- 2: its length
- 3: its shape
- 4: the size of its openings
How do large and small resonating cavities differ?
- the larger the resonating cavity (vocal tract), the LOWER the frequencies to which it will respond
- the smaller the resonating cavity (vocal tract), the HIGHER the frequencies to which it will respond
How do you solve for R1 of a male vocal tract?
- The lowest natural frequency at which a tube resonates has a wavelength (λ) four times the length of the tube
- Given: average vocal tract length (L) of 17cm;
- λ = 4(L)
- solve for λ: λ = 4(17cm) = 68cm
- λ = 68cm
What is the relationship between pressure and velocity in the vocal tract/resonating tube?
Air pressure and air particle velocity in resonating tube are inversely related:
- Closed end (glottis)
- air pressure is at a maximum
- air particle velocity must approach zero
- Open end (lips)
- air pressure is at a minimum
- air particle velocity must be at maximum
What are the major differences between vowel and consonant production? (source, filter)
- Constrictions used to produce sounds are usually more extreme than those for vowels
- various configurations of the vocal tract generate different combos of resonant frequencies (formants) for each sound
- Differences in the ways the sources of sound are used in the production of consonants
- vowels usually produced only w/ periodic sound source, consonants may use aperiodic or combo
What is a formant?
- a peak of resonance in the vocal tract
- the vocal tract acts as a resonator with frequencies which can be modulated by the articulators, forming the vocal formants which make vowel sounds recognizable
- formants are synonymous with resonant frequencies: R1=F1
Why do absolute formant values differ across speakers?
- speakers differ in overall tract-length
- parts of the vocal tract may vary in size: the pharynx is proportionally smaller in women
- speakers of the same language vary in dialect and idiolect (dialect unique to individual)
When is pressure at maximum and minimum?
- Air pressure is at maximum at the closed end (glottis)
- Air pressure is at minimum at the open end (lips)
- THIS IS INVERSE TO VELOCITY
When is velocity at maximum and minimum?
- Velocity is at maximum at the open end (lips)
- Velocity approaches zero at the closed end (glottis)
- THIS IS INVERSE TO PRESSURE
Suprasegmentals: Types
Suprasegmental (prosodic) features span units larger than a phoneme:
- Stress: applied to the syllable
- Intonation: applies to phrases and sentences
- duration: varies over many units in speech
- juncture: the way adjacent sounds are joined to or separated from one another
Suprasegmentals: Stress types (3)
-Lexical stress: stress patterns in words:
•For example, unicorn, immediate
•Varies between nouns and verbs in English
•For example, digest (noun) versus digest (verb)
-Sentential stress: emphasizes words in sentences:
•For example, “Is that your red book?” (not the green one)
-Contrastive stress may put emphasis on a normally weak syllable to clarify a contrast:
•Receive, not deceive
Characteristics of Stressed Syllables
Stressed syllables have:
-higher F0, increased vocal fold tension, higher subglottal pressure
-longer duration because the articulators move to more extreme positions
-greater intensity: higher subglottal pressure
Stress is relative: how a syllable relates to nearby syllables in the utterance depends on context
Lexical Stress: what is it, examples
- lexical stress is stress patterns in words
- UUUnicorn, iMEDiate
- it varies between nouns and verbs in English
- DIgest (noun) vs. diGEST (verb)
Vocal Tract: Pharynx
- Formed by a tube of constrictor muscles
- Posterior portion of vocal tract
- contracting these muscles narrows the pharynx, relaxation of the muscles widens it
- superior constrictors: at level of pharynx
- middle constrictors: at level of oropharynx
- inferior constrictors: at level of laryngopharynx
Vocal Tract: Oral Cavity
- formed by space btwn teeth, upper and lower jaws (maxilla, mandible), and tongue
- major oral landmarks for speech:
- teeth (esp incisors): production of dental sounds like “th”
- alveolar ridge: anterior region of hard palate: production of alveolars like /n, d, t, s/
- velum (soft palate): for velar sounds /k, g, ng/
Vocal tract: Velum
- Contracting levator palatini raises velum
- closes VP port
- separates nasal and pharyngeal cavities
- used for oral speech sounds
- Relaxation of the levator palatini causes velum to drop:
- opens VP port
- air flows freely into nasal cavity (breathing)
- velum MUST be lowered for nasal sounds
Vocal Tract: Tongue; extrinsic muscles (4 of them)
- 4 muscles connect tongue with external structures
- Styloglossus: up and back as in /u/ “sue”
- Hyoglossus: down and back as in “ah” (dr garcia kinda confused this on his slides)
- Genioglossus: up and forward, as for /i/
- Palatoglossus: up
Vocal Tract: Tongue; Intrinsic muscles (4 of them)
- 4 muscles run within the body of the tongue
- all contained within the tingue body
- provide fine shaping of tongue surface and tip
- Superior Longitudinal: raises tip as for /l/
- Inferior longitudinal: lowers tip as for /i/
- vertical muscle: runs superior-inferior, flattens tongue body
- transverse: runs left to right, narrows tongue body
Vocal Tract: Lips: muscles
- orbicularis oris encircles lips, used in bilabial closures /b p m/ and lip rounding /u/
- risorius draws lips back and up as in lip spreading for /i/
Intonation
- reflects changes in F0 in an utterance
- provides information on speaker affect: more F0 changes indicate heightened emotion
- can differentiate questions vs statements:
- declarative and wh-questions: rising-falling intonation pattern
- rising final intonation indicates yes/no
- final pitch rise indicates incompleteness
Control of intonation:
- increasing F0 results from higher vocal-fold tension
- decreasing F0 results from laryngeal and respiratory factors:
- relaxing CT muscle
- decreasing subglottal pressure
- the typical pattern is for F0 to fall at the end of a phrase/breath group
Assimilation: the basics, partial vs. complete
- Assimilation is when a sound becomes like its neighbor: one articulator is involved and it’s like a shortcut for the articulator
- Partial assimilation: no change in phonemic categorization, just an allophonic change
- Complete assimilation: phonemic class changes i.e. the /n/ becomes /ng/ in “Bank”
- Assimilation can be seen in acoustics, speech movements, muscle activity
Assimilation: Anticipatory vs. Carry-Over
Anticipatory (right to left, look ahead) assimilation:
-sound is influenced by the following sound, i.e. dentalization of /t/ in “eaT THe cake”
Carry-Over (left-to-right) coarticulation: one sound influenced by a previous sound
-i.e. “cats” and “dogs” have /s/ and /z/ phonemes
Assimilation of Place vs. Assim. of Manner vs. Assim. of Voicing
Assimilation of Place: /n/ turns into /ng/ in “ten cards”
Assimilation of Manner: “dyoo” turns into “dju” in “educate”
Assimilation of Voicing: plural /s/ being /s/ vs /z/ in “cats” and “dogs”
Speech in Context: Assimilation and Coarticulation
- Assimilation + Coarticulation are pervasive in speech
- in running speech, phonemes are not isolated segments
- IPA transcription represents speech as a series of “beads on a string”
- ordered sequentially in time
- independent of each other
- normal speech involves continuous movement- no ‘beads”
- phonemes are not clearly represented in the speech signal: they are mental abstractions
