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Fundamental Frequency -Average mass and length of the male adult's vocal folds are greater -Men have lower fundamental frequency than women and children Harmonic Spacing -Adult male spacing is closest together and children's spacing is furthest apart Muscle Control of Pitch -Longer vocal folds vibrate at lower frequencies -Tense vocal folds vibrate at higher frequencies -Less massive (thinner) vocal folds vibrate at higher frequencies -Cricothryroid muscles (CT) changes length and tension of vocal folds Gender differences in larynx: thyroid angle -Thyroid angle is more acute in men than women (120 degree in women 90 in men) Gender differences in larynx: posterior glottal chink -incomplete approximation during adduction in women air escapes creating a turbulent noise -increase in breathiness Gender differences in larynx: vocal fold length -men vocal fold length approx 17-24mm -women vocal fold range between 13-17mm Gender differences in larynx: mass -mass of the vocal folds is larger in men than in women Gender differences in larynx: fundamental frequency -Lower in men than women Male average: 130Hz Female average: 250Hz Hyper Adduction -Vocal abuse; takes more pressure to overcome resistance of vocal folds ex- Spastic Dysphonia Hypo Adduction Inappropriate usage; vocal folds do not offer enough resistance ex- vocal fold paralysis Laryngeal tissue change changes in vocal fold mass --> Fundamental frequency changes --> Reduced periodicity Nodules -benign growths on both vocal cords that are caused by vocal abuse -repeated abuse of vocal cords results in soft swollen spots, that develop into callous-like growths ex- callouses Polyps -sometimes caused by vocal abuse, polyps appear as a bump and become like a blister polyps are larger than nodules ex- blister Source-Filter Theory of Speech Production Amplitude - Frequency characteristics of the source vibration of the folds Frequency - Selective gain of vocal tract (resonance) Resonance of the vocal tract Tubes resonate naturally at frequencies that depend on the length and configuration of the tube Vowels vs. Consonants Vowels - a vocal sound produced by relatively free passage of the air stream through the larynx and oral cavity Consonant - one or more areas of vocal tract narrowing by some degrees of constriction (partial or complete) Independence of source/filter Hold source constant while changing filter maintain constant pitch Vary vowel (change from "ee" to "oo") Hold filter constant while changing source Source-Filter Theory of Speech Production: Laryngeal source The larynx produces complex periodic sound (fundamental frequency and higher harmonics) Source-Filter Theory of Speech Production: Resonance of the vocal tract -Vocal tract filters the sound source: -Harmonics near formant frequencies resonate and have high amplitudes -Harmonics far from formant frequencies are attenuated (filtered) Source-Filter Theory of Speech Production: Supraglottic source In speech, supraglottal cavities are shaped by the articulators Resonant frequencies determined partly by cavity size Resonances of the vocal tract are called formants Constriction at a Node Raises the formant frequency Constriction at an Antinode Lowers the formant frequency Constricting the vocal tract near a pressure maximum (minimal velocity) node raises the formant value ex- a constriction in the lower pharynx raises f1 Formant frequencies are lowered by... Labial Constriction Formant frequencies are raised by... Lowering mandible Spectrum Frequency by amplitude display Displays frequencies and amplitudes of resonances (formants) Generated using Linear Predictive Coding (LPC) Spectrogram displays all spectra computed from speech waveforms x-axis = time y-axis = frequency darkness of tract = intensity Traditional description of vowels: articulation vs. acoustically (formants) Traditional classification based on impressions of articulation: -tongue shape -tongue position Acoustic description based on formants: -f1 and f2 convey information on vowel quality -formant values correspond roughly to articulatory postures How F1 and F2 relate to resonant cavity: F1 volume of pharyngeal cavity influenced by tongue height How F1 and F2 relate to resonant cavity: F2 length of oral cavity influenced by tongue backing F1 Resonance Rule inversely related to jaw height as jaw goes down, F1 goes up F2 Resonance Rule directly related to tongue fronting as the tongue moves forward, F2 increases Pharyngeal cavity resonance F1 is high Oral cavity resonance F2 is relatively low Formants F1, F2, F3 in front vowels F1 increases F2 decreases F1 & F2 far apart F2 & F3 close together Formants F1, F2, F3 in back vowels F1 increases relationship to F2 is unclear How vowels vary between speakers Relative patterns of formant values are consistant across speakers Absolute formant values vary across speakers: -overall vocal tract length differences -parts of the vocal tract may differ in size -dialect Tense vowels Tense vowels: eg [i e o u] -involve more extreme articulators -have longer durations -can occur in open syllables eg [CV] -may be dipthongized eg [e i o u] Lax vowels -have less extreme articulatory postures -are shorter in duration -occur only in closed syllables eg [CVC] Dipthongs -a vowel with a change in quality during a single syllable, as in "high" on glide - articulatory starting position for dipthong off glide - ending articulation point Vowels in disordered populations Congetitally deaf speakers often have deviant vowel spaces: - jaw and tongue placements are more constrained than in hearing speakers impaired vowel production may be evident in apraxia of speech, dysarthria, and cerebral palsy -foreign accents may involve errors in vowel production -visual feedback eg (via spectrograms) may help speakers improve vowel production Consonant Place - Bilabial lips come together "ba" "pa" Consonant Place - Labiodental lips make contact with "f" Consonant Place - Lingualdental tongue comes between upper and lower tooth Consonant Place - Alveolar tongue tip touches alveolar ridge Consonant Place - Palatal when tongue touches the hard palate Consonant Place - Velar back of tongue touches the velum Consonant Place - Glottal purely sound passes through an open "h" Consonant Manner - Stops momentary complete blockage of air "pa" Consonant Manner - Fricatives two articulators come close together but don't touch creates hissing sound ex "s" Consonant Manner - Affricates when stops the fricatives come together Consonant Manner - Nasals only sounds that involve resonation in the nasal cavity rather than the oral cavity "m" "n" Consonant Manner - Approximates Liquid ( l, r air flows around side of tongue) Glides (tongue shifts from the front to back position) Consonant Voicing - Voiced Periodic laryngeal source Aperodic supralaryngeal source Consonant Voicing - Unvoiced Supralarynegeal source Sonorants vs obstruents and corresponding source sources: Sonorants Nasals, Liquids, Glides Similar to vowels m l yah n r w free airflow periodic laryngeal source call voiced Sonorants vs obstruents and corresponding source sources: Obstruents -increased constriction from sonorants -stops, fricatives, affricates -aperiodic sound source in UPPER VOCAL TRACT -voiced or voiceless Nasality Nasals require open velopharyngeal levator palatini muscle is relaxed nasal cavities form a resonant chamber Voice onset time and its relevance time between stop release and phonation onset Assimilation A sound becomes like its neighbor; one articulator is involved Coarticulation two articulators active at the same time for two sounds coarticulation may affect only part of the tongue Suprasegmental level: Stress: lexical stress patterns in words ex- unicorn, immediate varies between nouns and verbs in english Suprasegmental level: Stress: sentential emphasizes words in sentences Suprasegmental level: Stress: contrastive may put emphasis on a normally weak syllable to clarify a contrast: receive , not deceive Intonation: sentence level declarative/wh-sentence vs yes/no question -reflects changes in fundamental frequency over an utterance -provides information on speaker affect -can differentiate questions versus statements Duration Speech sound durations vary because of many factors -intrinsic duration ex-flip tap duration Dipthong longer, lax vowels shorter Phonetic context ex- syllable final consonant voicing affects preceding vowel duration Language (eg English) may have more extreme durational variations Types of Feedback External: auditory air and bone conducted sensations contribution assessed using various manipulations -delayed auditory feedback (DAF) -increasing/reduced amplitude: lombard effect limited contribution of auditory feedback because too slow role in refining targets and monitoring errors Types of Feedback External: tactile sensations of touch (light, touch, deeper pressure) from -articulators in contact -air pressure and flow Proprioceptive Feedback -sence of direction, velocity of movement, and position of articulators from sensors in joints tendons muscle spindles Internal Feedback -delivery of information from brain about motor commands prior to motor response itself -information would be relayed faster than for any other type of feedback -no direct evidence but -likely because of neural connections among brain's motor areas Central internal feedback system relatively fast Proprioceptive responce relatively fast External feedback slower X-ray microbeam -extremely thin x-ray beam used to track small lead or gold pellets attached to tongue with adhesive Advantage -rapid rate and accurate tracking -useful in study of coarticulatory effects, velocity and acceleration Disadvantage -expensive equipment -radiation exposure Electromagnetic midsagittal articulograph (EMA) -used to track movements of lips, soft palate, tongue, and mandible during speech -tracks articulators in migsagittal plane -receiver coil travels in alternating electromagnetic fields created by transmitter coils Advantages -rapid tracking rate -tracks multiple articulators simultaneously Disadvantages -only points are measured -kinematic data obtained only from midline points of tongue, lips, or jaw -invasive, bulky and placed on the subject's head Optotrak tracks movement of articulators w/ markers attached to the surface of the skin overlying the stucture to be examined, advantage: well suited to tracking lip and jaw motion in 3-D disadvantages: limited to external use because it cannot be used inside the mouth only fleshpoints are tracked, not entire structure markers or wires may interfere w/ truely natural speech Strain gauge for transducing structural movements, especially lip and jaw; allows tracking of articulator with loading (measurement technique) EPG The EPG consists of an artificial palate embedded with electrodes that record tongue contact with the palate during speech production. The artificial palate is connected to a computer display for analysis of tongue- palate contact patterns.