slp 330 final exam

Sharp vs broad tuning

Sharp tuning

• responds to small range of freqs

• vibration persists for long time (light damping)

• glass, tuning fork

Board tuning

• responds to large range of freqs

• vibration dies out quickly (heavy damping)

• sound in air, phone earpiece

Landmarks of the vocal tract

• Lungs: provide airflow for speech

• Larynx (voice box): contains vocal folds → vibrate to produce voiced sounds, remain open for voiceless, epiglottis: flap that prevents food from entering the airway

• Pharynx (throat): nasopharynx → connects to nose, oropharynx → connects to mouth, shapes sound resonants

• Oral cavity: lips, tongue, teeth, alveolar ridge, hard/soft palate

• Nasal cavity: adds resonance when velum lowered, blocked for non-nasal sounds

Source and filter

• Production of vowel is the product of 

  • the excitation (source) spectrum generated by the larynx

  • the frequency response (filter) of the vocal tract configuration.

• Any change in vocal tract configuration alters the frequencies at which the cavities resonate

• Size and length of the vocal tract also alter the frequencies at which the cavities resonate

• 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)

Formants

Concentration of acoustic energy around a particular frequency in the speech wave

• F1: vowel height

• F2: vowel advancement

• F3: overall vocal tract length and lip rounding

Acoustic resonators relative to speech and hearing

Vocal tract 

• Both air filled and closed at one end

• Vocal tract closed-end= vocal folds for voiced sounds

Ear canal

• Ear canal closed-end=eardrum

• 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

Factors related to resonance of air filled tubes

Air filled tubes resonate at certain 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

Length → Shorter tube = higher pitch (whistle). Longer tube = lower pitch (didgeridoo).

Shape → Narrow parts boost high notes; wide parts boost low notes.

Open/Closed Ends → Open at both ends (flute): Normal musical notes. Closed at one end (soda bottle): Deeper, hollow notes.

Air Speed → Warmer air = slightly higher pitch.

Softness Inside → Padded walls (like your throat) muffle the sound.

Solving for R1 of male vocal tract

Given: average vocal-tract length (L) of 17 cm

• Wavelength = 4 (L)

• Wavelength = 4(17) = 68 cm

Wavelength and frequency are related: f = c/wavelength

• C = 34,400 cm/s

• F = 34,400 / 68 = 506 Hz

• R1 = 506 Hz for a 17-cm vocal tract

Relationship between pressure and velocity in vocal tract

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.

Bernoulli effect 

[i] - “see”

• High vowel: tongue body is elevated into the oral cavity, leaving pharynx open

• Front vowel: high point of the tongue is anterior, behind the alveolar ridge

• Genioglossus muscle is active to draw tongue up and forward

• Cavity shapes: large pharynx, small oral cavity

• F1 (back or pharyngeal cavity resonance) is low

• F2 (front or oral cavity resonance) is high

[a] - “spa”

• Low vowel: jaw & tongue are lowered

• Back vowel: tongue is retracted into pharynx

• Anterior belly of digastric muscle is active to lower jaw

• Hyoglossus muscle is active to draw tongue down & back

• Cavity shapes: small pharyngeal cavity, large oral cavity

• F1 (back cavity resonance) is high

• F2 (front cavity resonance) is relatively low

[u] - “you”

• High vowel: tongue is raised out of pharynx

• Back vowel: tongue dorsum is raised and retracted toward velum

• Rounded vowel: lips are rounded and protruded

• Styloglossus muscle is active to raise and back tongue

• Orbicularis oris muscle is active to round lips

• Cavity shapes: large pharynx, large oral cavity, overall vocal tract lengthened by lip protrusion

• F1 is relatively low

• F2 is relatively low

Tense vowels: e.g. [i e o u]:

• Involve more extreme articulations

• Have longer durations

• Can occur in open syllables (e.g., CV)

• May be diphthongized (e.g. [eI oU])

Lax vowels: [e.g., I ε ʌ ʊ]

• Have less extreme articulatory postures

• Are shorter in duration

• Occur only in closed syllables (e.g., CVC)

Vowels across speakers

Relative patterns of formant values are consistent across speakers; for

• example, [i] “eat” has a low F1, and a high F2

Absolute (actual) formant values vary across speakers

• Speakers differ in overall vocal-tract length.

• Parts of the vocal tract may differ in size: The pharynx is proportionally smaller in women than men.

• Speakers of the same language vary in dialect and idiolect (unique to individual).

Vowels in clinical populations

• Congenitally deaf speakers often have misarticulated vowel productions

  • Q: Why would this population have deviant articulation?

  • A: lack of auditory input from others and inability to self-monitor productions

• Impaired vowel production may be evident in apraxia of speech, dysarthria, and cerebral palsy

• Foreign dialects may involve errors in vowel production

• Visual feedback (e.g., via spectrograms) may help speakers improve vowel production

Major differences between vowel and consonant production

Differences in the source and filter:

• Constrictions used to produce consonants are usually more extreme than those for vowels

  • Various configurations of the vocal tract generate different combinations 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 with periodic sound source, consonants may use aperiodic source or a combination

Sound sources of consonants

• Voiced consonants (includes all sonorants - nasals, liquids, glides): periodic laryngeal source

• Voiceless consonants: supraglottal noise sources - aperiodic laryngeal source ([h] noise, aspiration)

• Obstruents (stops, fricatives, affricates): supraglottal noise sources

  • Stop bursts: release built-up pressure; transient noise

  • Frication: air forced through a narrow channel becomes turbulent; sustained noise

    • Voiced obstruents combine periodic and aperiodic sources

Sonorants (nasals, liquids, glides) similar to vowels (consonant class)

• Free airflow; articulation shapes vocal-tract cavities

• Characterized mainly by formant frequencies

• Have a periodic laryngeal source (all voiced)

Obstruents (stops, fricatives, affricates) (consonant class)

• Blocked or restricted airflow

• Have aperiodic sound sources in upper vocal tract

• May be voiced or voiceless

Obstruents (stops, fricatives, affricates) (characterisitcs)

• Stop bursts: release built-up pressure; transient noise

• Frication: air forced through a narrow channel becomes turbulent; sustained noise

• Voiced obstruents combine periodic and aperiodic source

Approximates (liquids, glides) (chracterisitcs)

• Have limited articulatory constrictions that alter resonant frequencies (similar to vowels)

• Classification as consonants based on syllable position

• Consonants occur on periphery

• Vowels form the nucleus

Assimilation

•  A sound becomes like its neighbor; one articulator is involved – a shortcut for the articulator:

  • Partial assimilation: no change in phonemic category – allophonic changes

    • Example: Dentalization of /t/ before /ð/ in “eat the cake”

    • [t ̥ ] is not a new phoneme

  • Complete assimilation: Phonemic class changes:

    • Example: Velarization of /n/ before /k/ in “ten cards” “bank”

  • “anger” - /n/ becomes /ŋ/

  • [ŋ] contrasts phonemically with [n]

Coarticulation

Two articulators active at the same time for two sounds

• Example: lip rounding and tongue tip raising during the production of [t] in “too” or [s] in “stoop”

• In the tongue (tip, blade, dorsum), coarticulation may affect only part of the structure (e.g., the tongue body may move toward the next vowel during a [t] closure).

Velum and nasal/oral speech sounds

Most speech sounds are oral (non-nasal):

• Soft palate elevated against posterior pharyngeal wall

• Velopharyngeal (VP) port closed

• Levator palatini muscle active

 Degree of VP closure varies with phonetic context

• Tighter - for oral obstruents (require airtight seal) / “p t k”

• Moderate - for high vowels

• Looser - for low vowels

Nasals require open VP port (lowered velum):

• Levator palatini muscle is relaxed

• Palatoglossus muscle may actively lower velum

• Nasal cavities form a resonant chamber

In nasal stops, the oral cavity is blocked at the same places of articulation as for the stops:

• At the lips [m]

• At the alveolar ridge [n]

• At the soft palate [ŋ]

Suprasegmentals

Suprasegmental (or prosodic) features span units larger than a phoneme 

• Stress: applies to the syllable

• Intonation: applies to phrases & sentences

• Duration: varies over many units in speech

• Juncture: the way adjacent sounds are joined to or separated from each other.

Perception vs. Hearing

Hearing is the physiological response to sound waves, whereas perception is the ability to interpret the sounds in a linguistically meaningful way

Outer ear component

• pinna/auricle (external cartilaginous flap)

• external auditory meatus (EAM) - canal to tympanic membrane

Outer ear function

pinna

• funnels sound into EAM

• protects entrance to EAM

• assists in sound localization

EAM

• protects middle & inner ear

• cerumen & cilia filter foreign objects

• air filled cavity abt 2.5 cm long and open at one end

Middle ear components

• tympanic membrane: border outer & middle ear

• ossicles: malleus, incus, stapes

• muscles: tensor tympani, stapedius

• oval window: entry to inner ear

• eustachian tube: path to nasopharynx

Middle ear function

• overcome impedance mismatch

• possibly attenuate loud sounds via acoustic reflect - middle ear muscles

• equalizes internal & external air pressure variations via eustachian tube

Inner ear components

Vestibular system: sense of motion and position

• semicircular canals

• vestibule

cochlear: sense of hearing

• Basilar membrane: membrane runs the length of the cochlea and holds Organ of Corti

• Organ of Corti: situated on the basilar membrane; auditory receptor; contains hair cells

• Tectorial membrane: connective tissue that covers the cilia)

Inner ear function

hearing & balance

• cochlear converts vibrations to neural signals via hair cells on basilar membrane (freq coding: place & timing theories)

Top down process

Listener hears some of the message, makes a rough analysis, synthesizes it into something meaningful, while simultaneously analyzing phonetics, phonemics, morphemic, and syntactic components

Bottom up process

Listener takes auditory information then makes phonetic, then phonemic, then morphemic, then finally syntactic interpretations to derive meaning

Vowels acoustic cues

• Formant Frequencies (F1, F2, F3):

  • F1: Inverse correlate of vowel height (↑F1 = lower vowel, e.g., /æ/).

  • F2: Correlate of frontness/backness (↑F2 = fronter vowel, e.g., /i/).

  • F3: Lowered in rhotic vowels (e.g., /ɝ/ in "bird").

• Duration: Tense vowels (/i, u, e, o/) are longer than lax vowels (/ɪ, ʊ, ɛ, ʌ/).

• Spectral Tilt: Steeper tilt (less high-frequency energy) in back vowels.

Semivowels acoustic cues

• Formant Structure: Resemble vowels but shorter (~50–100 ms).

• /w/: Low F1 (~300 Hz), low F2 (~800 Hz) (like /u/).

• /j/: Low F1 (~300 Hz), high F2 (~2300 Hz) (like /i/).

• Smooth Transitions: No turbulence (unlike fricatives).

Diphthongs acoustic cues

• Formant Movement: Dynamic shift in F1/F2 (e.g., /aɪ/ in "ride" starts low F1 → high F2).

• Duration: Longer than monophthongs.

• Rate of Change: Faster transitions distinguish diphthongs from vowel sequences.

Nasals acoustic cues

• Nasal Murmur: Extra formants at ~250 Hz and ~2500 Hz.

• Antiformants: Spectral dips (due to nasal cavity damping).

• Formant Transitions: Similar to stops but weaker (e.g., /m/ has bilabial-like F2 transitions).

• Low-Energy: Weak high-frequency energy (above 3000 Hz)

Stops acoustic cues

Voicing:

• VOT: Voiced = short/negative VOT; voiceless = long VOT.

• F0 & F1 Onset: Higher F0 and lower F1 after voiceless stops.

Place:

• Burst Spectrum: Bilabials (low), alveolars (mid-high), velars (compact mid).

• F2/F3 Transitions: Velars show "pinch" (F2/F3 convergence).

Manner:

• Silent Gap: Closure period (50–100 ms).

• Abrupt Formant Onset: After release.

Fricatives acoustic cues

Voicing:

• Voiced fricatives have weaker noise + voicing bar.

Place:

• Spectral Peak: /s/ = high (~4–8 kHz); /ʃ/ = lower (~2–6 kHz); /f/ = diffuse.

Manner:

• Noise Duration: ~100–200 ms.

• Turbulent Spectrum: Aperiodic energy.

Affricates acoustic cues

• Combination of Stop + Fricative:

• Stop Phase: Silent gap + burst.

• Fricative Phase: Noise with postalveolar spectrum (like /ʃ/).

Voicing:

• /dʒ/ has voicing during closure; /tʃ/ is voiceless.

Factors that impact vowel formants as discussed in chapter 10

Affected by connected speech

• Continuous movement of the articulators causes changes in vocal tract shape which affects resonant peaks

Affected by phonemic context and rate of articulation

• E.g., juncture, duration, speaking rate, stress

• Increased speaking rate often produces a neutralized vowel (schwa)

Differing vocal tract sizes produce variation in resonating cavities

• E.g., men, women, children, age

Acoustic cues of supra-segmentals

Intonation:

• Changes in fundamental frequency

• Pitch changes over the course of an utterance

Stress:

• Cued by perceived pitch (most effective cue)

• Cued by syllable duration (less effective cue)

• Cued by loudness (least effective cue)

Juncture:

• the way adjacent sounds are joined to or separated from each other

• Cued by a variety of acoustic features: silence, vowel and/or consonant length, presence/absence of voicing & aspiration

Clinical implications – why it is important for the SLP to know the acoustic cues

• Precisely diagnose speech-hearing disorders.

• Tailor evidence-based interventions (e.g., biofeedback, minimal pairs).

• Enhance outcomes for clients with hearing loss, motor speech disorders, and accent differences.

Electromyography (EMG)

• Measures electrical activity of neural signals to muscles

• Hooked wire (inserted directly)/surface

Spirometer

• measures airflow during nonspeech tasks

• apparatus for measuring the volume of air inspired and expired by the lungs

Pneumotachograph or Rothenberg Mask

Flow of air during speech usually collected via face mask, Measures airflow during speech

Plethysmograph

• Provides a measure of respiratory volume changes during speech

• in sealed environment

Pneumography

Records thoracic and abdominal movement associated with speech breathing using body coils

Laryngoscope

a mirror in the oropharynx; gives view of VF during phonation

Stroboscope

tuned to speaker's f0 creates “slow-motion” view of the VFs during phonation

Fiberoptic endoscope (fiberscope)

• Light source and camera are introduced through nose into laryngopharynx

• Vocal-fold abduction & adduction can be viewed

• Also can be used to monitor velar movement

Transillumination (photoglottography, PGG)

Uses a light source to indicate changes in glottal area during phonation; measures the degree of VF separation

Electroglottography (EGG)

• Measures the degree of vocal fold contact during adduction

• Paired electrodes on either side of thyroid cartilage pass a small current across the larynx

Ultrasound

• Used for viewing articulatory movements

• Useful for imaging tongue contours

Palatography

• Measures contact between tongue and palate

• Requires an artificial palate with embedded transducers (prothesis)

Magnetic resonance imaging (MRI)

• Permits 3D image of entire vocal tract

• Person is placed in a magnetic field

Clinical implications for using instrumentation in practice

Physiological recording can provide immediate feedback on articulatory behavior

• Some methods may be difficult to use in clinical settings:

• Endoscopy (invasive)

• Magnetometry, MRI (expensive; requires technical support)

Methods more easily incorporated into clinical use:

• Ultrasound

• Pneumography

• Palatography

3. small resonating cavities of human vocal tract are

air space b/w larynx+trachea , teeth+cheeks, lips

not answers with nostrils or thyroid

15. rounded vowel articulated by dorsum of tongue raised towards roof of mouth by contraction of styloglosseous, raising tongue dorsum…

[u] - soup

33. 3 factors that affect formant vowels in otherwise healthy individuals

• affected by connected speech

• Affected by phonemic context

• rate of articulation