1. Voice Assessment: Instrumental

2. Instrumental Analysis of Voice
Electromyographic assessment: direct measure of muscle activity; used for localization of muscle
Aerodynamic assessment:
1. airflow rate & volume
2. subglottal (intraoral) pressure
3. laryngeal resistance
4. phonation threshold pressure

3. Instrumental Analysis of Voice
Acoustic recording & analysis:
1. fundamental frequency (Fo)
2. intensity (dB SPL)
3. signal/ noise ratio
4. perturbation measures
5. spectral frequencies
Electroglottography: measure of vocal fold contact area
Photoglottography: measure of glottal area

4. Why do instrumentation evaluation?
Contributes to the diagnosis, etiology and severity of the disorder,
Allows perceptual measures to be objectified (i.e documentable),
Instrumental evaluations are “noninvasive”,
Baseline for documentation of progress,

5. Electroglottography Noninvasive, inexpensive,
Demonstrates relative contact of the vocal folds during a glottal cycle,
No information concerning area of glottal opening,
Small electrodes on neck;
glottis opens= impedance rises,
glottis closes= impedance falls

6. Electrodes Glottis EGG Vocal fold contact area
Electroglottograph
electronics
Vocal fold
contact area
Lines between electrodes represent the electrical current traversing through the v.f.’s

7. EGG Signal (inverse filtered)
1000
Airflow
68 MSEC
EGG
Opening (upward trace); Closing (downward trace)
v.f.’s touch (close) = greater current

8. Width of area of glottis
Glottogram
OPEN
Point of max opening
Width of area of glottis
(% of Maximum)
CLOSED
Opening
Closing
Closed Phase
Open Phase
1 Cycle (T)

9. EGG: Normal & Disordered Glottal Waves
A. Normal glottal width function A. B.
Right Vocal fold
Right Vocal fold
Midline
Midline
Relative distance from midline
Relative distance from midline
Left Vocal fold
Left Vocal fold
Time of frame number
B. Left recurrent nerve paralysis (Left never reaches midline
& greater excursion; right fold crosses midline)

10. Electromyography Electrodes are either surface or needle,
Needle inserted into specific muscles
What do we look for?
1. onset & offset of muscle activity
2. pattern of muscle activity
4. amplitude of muscle activity
5. spont. bursts of activity
Useful for voice problems with neurological or neuromuscular etiology.

11. EMG: Hooked Wire Electrode

12. EMG Vowel Production CV Combos CT Voice CT Voice Long relaxation time
Buildup of EMG activity in CT ba ba ba
bababa da da
dadada

13. Aerodynamic
Define vocal efficiency through airflow rates & pressure changes,
Airflow rates: flow of air through the glottis,
measured using pneumotachography & body plethesmography
Subglottal pressure: driving pressure underneath the folds,
pitot tube & pressure transducer, tube placed in the oral cavity,
invasive method = esophageal balloon

14. Aerodynamic
Laryngeal resistance: peak intraoral pressure divided by peak flow rate, reflects the overall resistance of the glottis,
Phonation threshold pressure: minimal pressure to set v.f.’s into oscillation

15. Glottal Resistance
A. Increased in subglottal pressure
to overcome increase in glottal
resistance
B. Larynx offers increased resistance
to airflow as folds are placed under
increased tension
Intratracheal Pressure (cm H20)
Glottal resistance (dynes/se/cm)
Fundamental Frequency (% of Freq. range)
Fundamental Frequency (% of Freq. range)
*30% of F0= Most efficient function of the larynx or habitual pitch

16. Importance of aerodynamic results?
Results are a reflection of the valving activity of the larynx,
Represents v.f. configuration, movement, structure & function,
Intraoral pressure, transglottal airflow, & laryngeal resistance:
1. Discriminate normal & pathologic voice function,
2. Assess severity
3. Suggest implications for the diagnostic source of voice pathology

17. Acoustic
Fundamental frequency: rate of vibration of the vocal folds, expressed in Hertz, or cycles per second, measure on sustained vowel or connected speech,
Visipitch, C-Speech, CSL
Perturbation measures: cycle-to-cycle variation in a signal; jitter (frequency) & Shimmer (amplitude),
Signal to noise ratio: a measure of the energy in the voice signal over the noise energy in the voice signal, greater harmonic energy in voice= better voice quality,

18. Acoustic
Intensity: SPL (Sound Pressure Level), measure mean and range intensity,
Sound level meter or acoustic analysis programs
Spectral analysis: displays glottal sound source & filtered characteristics of the speech signal across time, useful to analyze changes in the spectral characteristics of the voice sound,
C-Speech, CSL

19. Spectographs Aperiodic v.f. vibration is evident by the irregularity
of the spacing of the vertical voice bars

20. Spectograhs: Voice Quality
Normal
Nasal
Breathy
Harsh
Hoarse

21. Spectographs: Vocal Nodules
A. Vocal Nodule
B. Aperiodic vocal fold vibration
& Noise
C. Six weeks post surgery

22. Importance of Acoustic Measures
Provide objective & noninvasive measures of vocal function
Normative values help you discriminate normal and pathological voice attributes
Measure change in vocal performance over time
Indirect inference about the severity of voice
No acoustic measures can differentially diagnose the source of the voice pathology

23. Case # 1 41 year old attorney 4 months dysphonia
Problem began after severe URI
chronic coughing & clearing
Long history of cigarette smoking ( 1 pack per day)
Moderate alcohol consumption
Voice abuser: home, sporting event, work

24. Examination Findings Mild-moderately hoarse- breathy
Dramatic pitch decrease (2 months)
Syllables per breath were normal
Maximum phonation time = 16 seconds
Acoustic:
F0= 105 hz
Jitter = 1.4%
Shimmer = .33 dB
S/N ratio = 12.7 dB

25. Examination Findings Aerodynamic: Mean airflow (l/sec)= 798 cc /sec
Subglottal pressure = 20 cm H20
Glottal resistence= 20 cm H20/lps
compressoin force between vocal folds during closed phase of vibration

26. Diagnosis Bilateral true vocal fold hemorrhagic polyps
secondary to voice misuse & abuse

27. Readings
Colton & Casper Ch.7 (Last half particularly)