SPPA 4030 Speech Science1 Phonation

SPPA 4030 Speech Science2 Topic Sequence Anatomy review Achieving phonation Capturing glottal and vocal fold behavior Phonatory control parameters Lifecourse considerations Clinical considerations

SPPA 4030 Speech Science3 Topic Sequence Anatomy review

SPPA 4030 Speech Science4 The hyo-laryngeal complex

SPPA 4030 Speech Science5 Extrinsic/Supplementary Muscles

SPPA 4030 Speech Science6 Intrinsic muscles

SPPA 4030 Speech Science7 Muscular Actions

SPPA 4030 Speech Science8 CA joint function

SPPA 4030 Speech Science9 Muscular actions on vocal folds Alter position –Adduction LCA, IA, TA –Abduction PCA Alter tension (and length) –Increase/decrease longitudinal tension Balance between TA and CT

SPPA 4030 Speech Science10 Extrinsic/supplementary muscles Holds the larynx in the neck Allows positional change of the larynx –Elevates when swallowing –Elevates during certain speech activities Elevating pitch High vowel production

SPPA 4030 Speech Science11 The larynx

SPPA 4030 Speech Science12 “Layered” structure of vocal fold

SPPA 4030 Speech Science13 Basic Structure of the vocal fold epithelium connective tissue superficial layer tissue loosely connected to the other layers intermediate layer elastic fibers deep layer collagen fibers (not stretchy) muscle (TA) Vocal ligament Lamina propria

SPPA 4030 Speech Science14 Topic Sequence Anatomy review Achieving phonation –Features of the mucosal wave –Two-mass model of phonation –More complex models of phonation

SPPA 4030 Speech Science15 Vocal fold vibration (mucosal wave) Vertical phase difference

SPPA 4030 Speech Science16 2-mass model Lower part of vocal fold Upper part of vocal fold Mechanical coupling stiffness TA muscle Coupling between mucosa & muscle

SPPA 4030 Speech Science17 Myoelastic aerodynamic theory of phonation Necessary & sufficient conditions for phonation 1.Adduction 2.Longitudinal tension 3.Aerodynamic pressures

SPPA 4030 Speech Science18 VF adducted & tensed → myoelastic pressure (P me ) Glottis is closed subglottal air pressure (P sg ) ↑ P sg ~ 8-10 cm H 2 0, P sg > P me L and R M1 separate Transglottal airflow (U tg ) = 0

SPPA 4030 Speech Science19 As M1 separates, M2 follows due to mechanical coupling stiffness P sg > P me glottis begins to open P sg > P atm therefore U tg > 0

SPPA 4030 Speech Science20 U tg ↑ ↑ since glottal aperature << tracheal circumference U tg ↑ P tg ↓ due to Bernoulli effect

SPPA 4030 Speech Science21 Bernoulli’s law P + ½  U 2 = K where P = air pressure  = air density U = air velocity

SPPA 4030 Speech Science22 U tg ↑ P tg ↓ due to Bernoulli effect P tg < P me M1 returns to midline

SPPA 4030 Speech Science23 M2 follows M1 due to mechanical coupling stiffness ‘other’ aerodynamic effects U tg = 0 Pattern repeats times a second

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SPPA 4030 Speech Science25 Limitations of this simple model Actual VF movement is more complex Vocal folds have length and vary in biomechanical properties along their length

SPPA 4030 Speech Science26 Added features of vocal fold vibration (mucosal wave) Longitudinal phase difference

SPPA 4030 Speech Science27 Topic Sequence Anatomy review Achieving phonation Capturing glottal and vocal fold behavior –Flow glottogram –Electroglottogram –Photoglottogram –Visualization: stroboscopy & high speed –Acoustic waveform analysis

SPPA 4030 Speech Science28

SPPA 4030 Speech Science29 Topic Sequence Anatomy review Achieving phonation Capturing glottal and vocal fold behavior –Photoglottogram –Visualization: stroboscopy & high speed –Flow glottogram –Electroglottogram –Acoustic waveform analysis

SPPA 4030 Speech Science30 Estimating glottal area Photoglottography (PGG) Videolaryngoscopy –Stroboscopy –High speed video

SPPA 4030 Speech Science31 Photoglottography (PGG) Time illumination

SPPA 4030 Speech Science32 Glottal area waveform

SPPA 4030 Speech Science33 Estimating degree of VF contact Electroglottography (EGG)

SPPA 4030 Speech Science34 Electroglottography (EGG) Human tissue =  conductor Air:  conductor Electrodes placed on each side of thyroid lamina a high frequency, low current signal is passed between them VF contact  =  impedance VF contact  =  impedance

SPPA 4030 Speech Science35 Time illumination 1/impedance PGG EGG

SPPA 4030 Speech Science36 Estimating airflow (volume velocity) Flow glottogram

SPPA 4030 Speech Science37 Time illumination 1/impedance PGG EGG Glottal airflow

SPPA 4030 Speech Science38 Consequence of this vibration Air disturbance is caused by the “slapping” together of the vocal folds Sound energy is maximum at glottic closure Given the complexity of the vibratory patterns of the vocal fold, the sound produced at the glottis is complex and periodic.

SPPA 4030 Speech Science39 Glottal waveform (Time domain) ‘triangular’ shaped Looks simple, but is complex

SPPA 4030 Speech Science40 Glottal waveform (Frequency domain) 12 dB/octave roll off Octave: doubling of frequency Harmonics: integer multiples of the fundamental frequency (F 0 )

SPPA 4030 Speech Science41 Is this what we see coming from the mouth? NO Glottal spectrum is shaped by the resonant characteristics of the vocal tract

SPPA 4030 Speech Science42 Recall… Air disturbance is caused by the “slapping” together of the vocal folds Sound energy is maximum at glottic closure

SPPA 4030 Speech Science43 illumination 1/impedance PGG EGG Glottal airflow Sound pressure

SPPA 4030 Speech Science44 Pressures needed to initiate vibration Phonation threshold pressure –Minimum pressure needed to set the vocal folds into vibration –3-6 cm water –~3 for low Fo, 6 for higher Fo –Higher for louder speech

SPPA 4030 Speech Science45 Topic Sequence Anatomy review Achieving phonation Capturing glottal and vocal fold behavior Phonatory control parameters –Fundamental frequency control –Amplitude control –Register control –Phonatory quality control –Phonation onset –Articulatory control

SPPA 4030 Speech Science46 Fundamental Frequency Control Fundamental frequency (Fo) = reflects rate of vibratory cycle

SPPA 4030 Speech Science47 F o Control Anatomical factors Males ↑ VF mass and length = ↓ F o Females ↓ VF mass and length = ↑ F o Subglottal pressure adjustment – show example ↑ P sg = ↑ F o Laryngeal and vocal fold adjustments ↑ CT activity = ↑ F o TA activity = ↑ F o or ↓ F o Extralaryngeal adjustments ↑ height of larynx = ↑ F o

SPPA 4030 Speech Science48 Fundamental Frequency Average F 0 sustained vowels or spontaneous speech For “connected” speech, it is called speaking fundamental frequency (SFF) Typical or ‘normative’ values depend on gender and age

SPPA 4030 Speech Science49 Fundamental Frequency Average F 0 Infants~ Hz Boys & girls (3-10) ~ Hz Young adult females~ 220 Hz Young adult males~ 120 Hz Older femalesdrops Older malesincreases

SPPA 4030 Speech Science50 F 0 variability F 0 varies due to –syllabic stress –emphatic stress –grammatic and semantic factors –Phonetics (in some languages) Provides a melody to speech (prosody)

SPPA 4030 Speech Science51 F 0 SD (Hz) or pitch sigma (semitones) reflects the spread of values around the average F 0 May be measured in semitones (12 semitones = 1 octave) rather than Hz ~2-4 semitones for normal speakers

SPPA 4030 Speech Science52 F 0 Range (in a speaking task) Maximum F 0 - minimum F 0 Infants~1200 Hz Boys & girls (3-10) ~ Hz Young adult females~ 100 Hz Young adult males~ Hz

SPPA 4030 Speech Science53 Maximum Phonational Frequency Range Not measured during speech highest possible F 0 - lowest possible F 0 measured in Hz, semitones or octaves Males~ Hz Females~ Hz 3 octaves often considered normal

SPPA 4030 Speech Science54 Ways to measure fundamental frequency Time domain vs. frequency domain Manual vs. automated measurement

SPPA 4030 Speech Science55 How do we measure Fo? Computer-based acoustic analysis programs –e.g. tf32!!, as well as many others Electronic equipment specially designed to extract Fo and amplitude measure –e.g. Kay Elemetrics Visipitch

SPPA 4030 Speech Science56 Topic Sequence Anatomy review Achieving phonation Capturing glottal and vocal fold behavior Phonatory control parameters –Fundamental frequency control –Amplitude control –Register control –Phonatory quality control –Phonation onset –Articulatory control

SPPA 4030 Speech Science57 Amplitude Measured as Pressure or Intensity Subglottal pressure adjustment ↑ P sg = ↑ sound pressure Laryngeal and vocal fold adjustments ↑ medial compression = ↑ sound pressure Supralaryngeal adjustments

SPPA 4030 Speech Science58 Average sound pressure level conversation:~ dB SPL

SPPA 4030 Speech Science59 Sound pressure variability  SPL to mark stress Adds to speech prosody Standard deviation for neutral reading material: ~ 10 dB SPL

SPPA 4030 Speech Science60 Dynamic Range Amplitude analogue to maximum phonational frequency range ~50 – 115 dB SPL

SPPA 4030 Speech Science61 How do we measure amplitude? Computer-based acoustic analysis programs –e.g. tf32!!, as well as many others Electronic equipment specially designed to extract Fo and amplitude measure –e.g. Kay Elemetrics Visipitch Sound level meter (amplitude only) Old-fashioned equipment like an oscilloscope

SPPA 4030 Speech Science62 Combining F 0 & Amplitude Voice Range Profile Plots dynamic range as a function of phonation range

SPPA 4030 Speech Science63 Voice Range Profile

SPPA 4030 Speech Science64 Topic Sequence Anatomy review Achieving phonation Capturing glottal and vocal fold behavior Phonatory control parameters –Fundamental frequency control –Amplitude control –Register control –Phonatory quality control –Phonation onset –Articulatory control

SPPA 4030 Speech Science65 Vocal Register Refers to a distinct mode of vibration According to Hollien… Range of consecutive F o s produced with a distinct voice quality F o range should have minimal overlap with other registers

SPPA 4030 Speech Science66 Vocal Register Pulse register (a.k.a. vocal fry, glottal fry, creaky voice) Modal register (a.k.a. chest register) Falsetto register (a.k.a. loft register)

SPPA 4030 Speech Science67 Vocal Registers Pulse (Glottal fry) –30-80 Hz, mean ~ 60 Hz –Closed phase very long (90 % cycle) –May see biphasic pattern of vibration (open, close a bit, open and close completely) –Low subglottal pressure (2 cm water) –Energy dies out over the course of a cycle so parts of the cycle has very little energy –Hear each individual cycle

SPPA 4030 Speech Science68 Vocal Registers Modal –VF are relatively short and thick –Reduced VF stiffness –Large amplitude of vibration –Possesses a clear closed phase –The result is a voice that is relatively loud and low in pitch –Average values cited refer to modal register

SPPA 4030 Speech Science69 Vocal Registers Falsetto – Hz ( Hz males) –VF are relatively long and thin –Increased VF stiffness –Small amplitude of vibration –Vibration less complex –Incomplete closure (no closed phase) –The result is a voice that is high in pitch

SPPA 4030 Speech Science70 Topic Sequence Anatomy review Achieving phonation Capturing glottal and vocal fold behavior Phonatory control parameters –Fundamental frequency control –Amplitude control –Register control –Phonatory quality control –Phonation onset –Articulatory control

SPPA 4030 Speech Science71 Vocal Quality Doesn’t have clear acoustic correlates like pitch and loudness some acoustic measures that have potential to be helpful in characterizing voice qualities

SPPA 4030 Speech Science72 Voice Quality Common Terms Breathiness Tense Roughness Strain Hoarseness

SPPA 4030 Speech Science73 Voice Quality Auditory Perceptual Descriptors Breathiness –Audible air escape in the voice –Diminished or absent closed phase –Correlated with high frequency noise sharper harmonic roll-off lower signal-to-noise ratio (SNR)

SPPA 4030 Speech Science74 Roll-off

SPPA 4030 Speech Science75 Signal (harmonic)-to-noise-ratio (SNR or HNR) Glottal spectrum is not strictly periodic Periodic component –Periodic cycling of vocal folds Noise component –Aperiodicity in cycling –Air “leakage” (Additive noise)

SPPA 4030 Speech Science76 Signal (harmonic)-to-noise-ratio (SNR or HNR) ratio of signal amplitude to noise amplitude  SNR –Relatively more signal –Indicative of a normality  SNR –Relatively more noise –Indicative of disorder Normative values depend on method of calculation “normal” SNR ~ 15

SPPA 4030 Speech Science77 Signal (harmonic)-to-noise-ratio (SNR or HNR) signal Noise ‘floor’

SPPA 4030 Speech Science78 Signal (harmonic)-to-noise-ratio (SNR or HNR) signal Noise ‘floor’

SPPA 4030 Speech Science79 Voice Quality Auditory Perceptual Descriptors Tense or Pressed –Perceptually contrasted with breathiness –Correlated longer closed phase Less harmonic roll off

SPPA 4030 Speech Science80 Roll-off

SPPA 4030 Speech Science81 Voice Quality Auditory Perceptual Descriptors Roughness –Perceived cycle-to-cycle variability in voice –Correlated with jitter (frequency perturbation)

SPPA 4030 Speech Science82 Cycle to cycle variability in vibration Vocal fold vibration not strictly periodic ↓ frequency and amplitude fluctuations are normal When variability is excessive, it sounds abnormal

SPPA 4030 Speech Science83 Frequency variability Variability in the period of each successive cycle of vibration Termed frequency perturbation or jitter …

SPPA 4030 Speech Science84 Amplitude variability Variability in the amplitude of each successive cycle of vibration Termed amplitude perturbation or shimmer

SPPA 4030 Speech Science85 Sources of jitter and shimmer Small structural asymmetries of the L and R vocal fold “material” on the vocal folds (e.g. mucus) Biomechanical events, such as raising/lowering the larynx in the neck Small variations in tracheal pressures “Bodily” events – system noise

SPPA 4030 Speech Science86 Measuring jitter and shimmer No standard measurement approach Variability in how measures are is reported Jitter: typically reported as %, but can be msec Normal ~ % Shimmer: can be % or dB Normal ~ 0.5 dB

SPPA 4030 Speech Science87 Jitter demo

SPPA 4030 Speech Science88 Topic Sequence Anatomy review Achieving phonation Capturing glottal and vocal fold behavior Phonatory control parameters –Fundamental frequency control –Amplitude control –Register control –Phonatory quality control –Phonation onset –Articulatory control

SPPA 4030 Speech Science89 Phonatory onset Timing of respiratory and phonatory activities –Simultaneous vocal attack –Hard glottal attack –Breathy attack

SPPA 4030 Speech Science90 Topic Sequence Anatomy review Achieving phonation Capturing glottal and vocal fold behavior Phonatory control parameters –Fundamental frequency control –Amplitude control –Register control –Phonatory quality control –Phonation onset –Articulatory control

SPPA 4030 Speech Science91 One other important role of phonation ITS ABSENCE Many sounds are voiceless Laryngeal devoicing gesture –Rapid abduction of vocal folds

SPPA 4030 Speech Science92 Clinical Considerations Abnormal voice: dysphonia Factors underlying dysphonia –Disease to laryngeal tissue –Neurologic and neuromuscular disease –How the voice is used –Muscle tension –Psychological factors

SPPA 4030 Speech Science93 Clinical Considerations Can we phonate without our larynx?