voice disorder evaluation

1. Disorders of Voice
Dr Sandeep Shrestha
2nd year resident
ENT
NMCTH

2. Road map
• Introduction
– Definition of Voice
– Mechanism of Production of voice
• Assessment of voice disorder
• Treatment overview
• Types of voice disorder

3. Definition of voice
Voice is the product of the vibrating vocal folds,
combined with the resonation of the sound
throughout the vocal tract.
Voice = Voiced Sound + Resonance + Articulation

4. Phonatory system divided into 3 levels
• The voice activating air stream(the respiratory
system).
• The voice generator ( the larynx with its vocal
fold) which causes the air to vibrate and thus
produce the tone.
• The voice resonator (the pharyngeal and oral
cavity) which selectively transmits some
frequency bands (called formants) and weakens
others (antiresonances).

5. • Pre-phonatory inspiratory phase : vocal fold
rapidly abduct to allow the intake of air.
• Subsequently vocal fold are adducted by
contraction of lateral cricoarytenoid muscles.
• Subglottic pressure air pressure increases below
the adducted vocal folds until it reaches a level
that overcomes the resistance and blow them
apart thus setting in motion the vibratory cycle
which result in phonation.

6. • Amount of pressure required to begin voicing is
phonation threshold pressure.
• Pulmonic air exhaled between the adducted vocal
folds producing vocal note.
• Production of vocal note is the result of repeated
vibratory movement of the vocal folds known as
vocal fold oscillation.

7. • Each vibratory cycle consists of 3 phases
– Adduction
– Aerodynamic seperation
– Recoil
• Subglottic air pressure overcomes the resistance
of the adducted vocal folds – vocal fold peel apart
form the inferior border.
• When finally separated at their superior margin –
puff of air is released.

8. • -ve pressure in glottis result in rapid closing of
vocal folds (due to bernoulli effect)
• Contact between the vocal folds increases until
the subglottic air pressure is high enough to blow
the vocal folds apart and cycle recommences.

9. Vocal fold vibration

11. Period of vocal fold contact and lack of contact in
one vibratory cycle divided into
• Closing phase : the vocal fold begins to close
rapidly from their lower margin.
• Closed phase : the medial edges of the vocal folds
are in full contact.
• Opening phase : the vocal folds begins to
separate from their lower margin and gradually
peel apart
• Open phase : vocal fold are seperated.

12. • Vocal folds have to be structurally and
functionally symetrical, at the same level and
close rapidly – clear vocal note.
• Insufficiency approximation of Vocal fold –air
wastage and production of breathy voice quality.
• Three parts of the oropharyngeal resonator are of
special interest:
– Laryngeal entrance immediately above the glottis
– Middle part with the velopharyngeal valve
– Outermost part between the lip

13. • Firm wall transmit the sound without loss of high
frequency components.
• Soft wall absorbs parts of the sound energy
spectrum.

14. Vocal registers(characteristis of vocal fold adduction
and vibration)
• Registers have been regarded as the perceptually
distinct regions of vocal quality over certain ranges
of pitch and loudness.
• 3 main vocal register
– Loft register(or falsetto)
– Modal register
– Pulse register(or glottal fry or vocal fry or creaky
voice)

15. Register may include Equivalent
terms
Vocal folds Fo range(Hz)
Loft
register
Highest vocal frequency Falsetto Thin, tense,
lengethen,
minimal
vibration
275-1100
Modal
register
Range of fundamental
frequencies most
commonly used in
speaking and singing
Chest,
head,
middle,
heavy voice
Complete
adduction
100-300
Pulse
register
Lowest range of vocal
frequencies, laryngeal
output is perceived as
pulsatile
Vocal fry,
glottal fry,
creaky
voice
Long closed
phase
20-60

16. Characteristic of the sound source/glottal signal
Voice quality
• Depends on the vibratory characteristics of the
laryngeal structures.
• Nature of vocal fold adduction during phonation
and the regularity of the mucosal waves of the
lamina propria.
• Regular vocal fold behaviour also requires a
stable airflow to generate vibration of the
laryngeal structure.

17. • Incomplete adduction-breathy voice ,whisper
• Irregular mucosal waveform vibration- aperiodic
sound hoarse (inflammation, focal lesion, muscle
imbalance)
• Vocal fold strongly adducted – pressed or
strained voice quality (often supraglottic
involvement)

18. Voice frequency
• Number of vibratory cycles per second (measured
in hertz)
• Rate of vibration of vocal folds is a function of the
fold length, elasticity, tension and mass and their
subsequent resistance to subglottal air pressure.

19. • Increase frequency – lengthening of the vocal
folds/ subsequent thinning and stiffening of the
vocalis muscles.
• Perceptual corelation of frequency is pitch.

20. Voice amplitude
• Vocal loudness is the perceptual corelation of
amplitude – the size of the oscillation of the vocal
folds.
• Amplitude of these vibration – depends – force of
the transglottal airflow.

21. Definition of voice disorder
• Not audible, clear or stable in wide range .
• Not appropriate for gender and age.
• Not capable of fulfilling its linguistic and
paralinguistic functions.
• Fatigues easily.
• a/w discomfort and pain on phonations.

22. Key definitions
Dysphonia: Any impairment of voice or difficulty speaking
Dysarthria: Difficulty in articulating words, caused by
impairments of muscle used in speech
Dysarthrophonia: Dysphonia in conjunction with dysarthria
e.g MND,CVA
Dysphasia: Impairment of comprehension of spoken or
written language(sensory dysphasia) or impairment of the
expression by speech or writing(expressive dysphasia)
Hoarseness: perceived rough, harsh or breathy quality of the
voice.
Odynophonia: pain while talking

23. Assessment of voice disorder

24. History of Voice Disorder
History includes :
• The chief complaint of voice disorder
• The description of:
–How it occurred
–Onset
–Duration
–How often it happens
–Aggravating and relieving factor
• Patient’s job
• Relationship in the family, at school or in the patient’s job
• Detailed medical health evaluation including:
– possible precipitating causes
–Voice use history
–Prior evaluation and other treatments (if any)

25. General examination
• Examination of throat, nose and ear
• Examination of neck
• Examination of central nervous system

26. Indirect laryngoscopy
• Vocal fold are observed in quiet and deep
breathing and while performing following
manoeuvers
– Producing a low voice
– Coughing with a short dry cough
– Producing high falsetto and a sharp loud voice
• Estimated length is noted

27. Objective evaluation of voice
• Perceptual evaluation of voice – using rating scale –
hoarseness, roughness.
• Acoustic analysis – fundamental frequency, intensity.
• Electrolaryngography/ electroglottography
• Visual assessment – laryngoscopy, stroboscopy
• Aerodynamic measures – subglottal pressure and flow
• Quality of life measure – voice handicap index
• Voice accumulator and test of vocal loading
• Combined measures – dysphonia symptoms index.

28. Perceptual evaluation of voice
1)GRBAS
• Grade : severity of abnormality of voice
• Roughness : perceived irregularly in voice
• Breathiness : audible or air escape on the voice
• Asthenia : weakness
• Strain : perception of excessive vocal effort
Speech and language therapists score their patients
from 0-3 in each
2)CAPE-V- Consensus Audi Perceptual Eval.- Voice
3) VPA- Vocal Profile Analysis

29. Visual perceptual scale
◦ General appearance
◦ Posture, breathing & musculo-cutaneous
tension
◦ Neurologic dysfunction
◦ Physical dys-morphology
◦ Physical manifestation of systemic diseases

30. Acoustic assessment
• Provides quantitatives measures based on the voice
signal(waveform and spectrum) recorded using a
microphone placed near a mouth.
• Microphone acts as transducer and convert acoustic
signal into an electrical signal.
• Voice material
• Sustained vowels
• Fluent speech
• Consonant – vowel sentences
• Inform about- sound duration, loudness, pitch, spectral
context- static & dynamic pitch changes.

31. Voice range profile (phonetogram)
• Is a visual display of the dynamic range of voice in
terms of frequency and vocal intensity.
• Used in both adults and children
• Usually produced by recording the patient ability
to produce sustained vowel.

32. Electrolaryngography
• Consists of two elctrodes placed on the skin on
either side of the thyroid cartilage.
• High frequency current ( 3 megahertz) is applied
between the electrodes and held at a constant
voltage.
• Vocal fold vibration changes the electrical
conductance between the electrodes.
• Resulting waveform can be analysed automatically
to obtain measures of the rate of vocal fold
vibration and frequency perturbations.

33. laryngoscopy
• Indirect laryngoscopy
• Rigid laryngoscopy
• Flexible laryngoscopy

34. Flexible laryngoscopy
• Endoscope is passed through the anterior
nares, along the floor of the nose under the
inferior turbinate.
• Once the endoscope is in postnasal space, the
patient is asked to inspire through the nose –
opens the postnasal sphincter allowing
passage of the endoscope into the
oropharynx.

36. Laryngeal stroboscopy
• Necessary to evaluate the vibratory patterns of
the vocal folds.
• Caried out in the same manner as conventional
laryngoscopy.
• However, normal light source is replaced by
flashing xenon-tube.
• Stroboscopic light source can be linked to a
hopkins rod or fiberscope.

37. • Both can be used for video display and recording
of image.
• Advantage over conventional laryngoscopy when
during phonation medial edge is clearly
visualized.
• Microphone signal ensure synchronization of the
fashes of light with the vibration of vocal cord.

38. • Larynx is visualized for only brief periods in the
range 1/1000 second.
• These brief images sample from various point
across many vibratory cycle, are fused together to
provide apparent slow motion of the laryngeal
vibration tissue.

40. Key features in the interpretation of
laryngostroboscopic :
1)Glottic closure pattern
anterior or posterior gap
hourglass or spindle shaped
irregular or regular
closed phase

41. 2)Mucosal wave in response to changes in pitch and
loudness
• symmetry of amplitude
• periodicity(regular/variable/irregular)
• degree of change (absent/decreased/increased)
3)Degree of lesion : color, shape, multiple/single,
surface

42. 4)Vocal fold opening/ closing pattern
• Range full / reduced
• Normal / lag
• Presence of spasm/tremor
5)Supraglottic apperance
• False cords medial constriction
• Anteroposterior constriction
• Prominence / lesion
6)Symmetry of arytenoid

43. Treatment overview
Ideally patient should be assessed in a
multiprofesional voice clinic by a laryngologist
and voice therapist and a joint treatment plan
should be formulated.
1)Vocal hygiene, lifesyle and dietary advice
2)Voice therapy
3)Medical treatment
4)phonosurgery

44. Vocal hygiene, lifesyle and dietary
advice
• Patient are explain about how the voice work
• The links between lifestyle, phonatory and non
phonatory vocal activities and stress on voice
disorder.
• The traumatic effect to the vocal folds such as
talking or singing too loudly, talking too fast,
shouting, throat clearing and harsh coughing.
• Communicating effectively without raising or
straining the voice,e.g. using a whistle in the
school playground

45. • Importane of adequate hydration for vocal fold
function, i.e. by drinking water and use of steam
inhalation, and avoiding excessive amounts of
drinking caffeine
• Smoking cessation, reducing, alcohol and social
drug consumption (particularly spirits, cannabis
and cocaine) and avoiding exposure to fumes,
dust and dry air.
• Diet and reflux reduction, e.g avoid eating late at
night, large or fatty meals.

46. Voice therapy
• Mainstay of treatment for muscle tension
dysphonia (MTD).
• Individual course of therapy, usually for no longer
than 8 sessions or in group.

47. Aims
• To help the patient to find a better voice quality
which is stable, reliable and less effortful to
produce.
• To make better use of vocal resonance and tonal
quality.
• To increase the flexibilty of the voice by
improving the pitch range and loudness without
undue effort.
• To increase the stamina of the voice.

48. Various technique are:
• Vocal exercises with the aim of targeting and
strengthening specific muscle groups and improving
glottal closure and effiency.
• Increasing awareness of and reducing excessive
tension in the muscles around the larynx, neck and
shoulders.
• Advice on posture and improving breathing during
speech.
• Laryngeal massage.
• General relaxation exercises and stress management.
• Psychological counselling.

49. Medical treatment
• Treatment of acid reflux.
• Treatment of URTI.
• Treatment of allergies.

50. Phonosurgery
• Surgery designed primarily for the maintainance,
restoration or enhancement of the voice.
• It emcompasses :
– Phonomicrolaryngoscopy
– Injection laryngoplasty
– Laryngeal framework surgery
– Recurrent laryngeal nerve reinnervation
– Laryngeal pacing

51. Microlaryngeal surgery
• Examination of the larynx usually under GA to
further establish a diagnosis, but more
importantly to surgically treat a pathology with
the aim of improving voice.
• Done using a suitable sized rigid laryngoscope.

52. Advantages
• Binocular vision
• Magnification
• Better illumination
• The ability to use bimannual instrumentation
• The ability to use the carbon dioxide laser.

53. Conventional microlaryngeal surgery
Laser mircosurgery : CO2, KTP,diode
Laryngeal microdebrider

54. Injection laryngoplasty
• This procedure aims to medialize an adductor
vocal cord palsy where cord is in a lateral
position.
Various material used are
• Teflon
• Fat
• Glycerine
• Collagen
• Silicone
• Calcium hydroxyapatite

55. Laryngeal framework surgery
• First described by Isshiki in 1974.
• Procedure on the laryngeal cartilage to change the
position or tension on the vocal cords in order to
achieve the desired voice outcome.

56. • Isshiki’s functional classification of thyroplasty
– Type I – medialization
– Type II – lateralization
IIa – lateral approach
IIb – medial approach
- Type III – relaxation (shortening )
- Type IV – tensioning (Lengthening)
IVa – cricoid approximation
IVb – tensioning by lateral approach

57. Recurrent laryngeal nerve
reinnervation
• The paralyzed vocal cord can be reinnervated to
restore its function.
• Two techniques
– Non selective reinnervation
• indicated in hoarseness due to unilateral adductor vocal
paralysis.
• Under GA via ipsilateral neck incision at the level of the
cricoid cartilage
• Ansa cervicalis and recurrent laryngeal nerve are
identified and anastomosed using a 9/0 nylon suture.
– Selective reinnervation

58. Selective reinnervation
• Indicated in stridor due to bilateral abductor
vocal cord paralysis.
• Under GA via an extended anterior neck skin
incision at the level of the cricoid cartilage.
• C3 root of the phrenic nerve is identified on one
side and anastomosed with a cable graft
harvested from the great auricular nerve in a Y
shape which is then inserted into both posterior
cricoarytenoid muscle.

59. • Next step involves identification of the
descending branch of the ansa hypoglossi and
recurrent laryngeal nerve on both side of neck
and anastomoses carried out between these
nerve bilaterally.

60. Laryngeal pacing
• This technique still being evaluated in clinical
trials.
• Involves inserting an electrode into each
posterior cricoarytenoid muscle which then
causes automatic abduction and adduction
movement of the vocal cords.
• Electrode is connected to an external placing
device that is surgically fixed under the skin on
the chest wall.

61. Thank you