COMDIS415 VOICE DISORDERS Flashcards
Speech Subsystems
- Respiratory system
- Laryngeal system
- Supralaryngeal systems (resonatory/articulatory)
MUSCLE ACTIVITY FOR RESPIRATION (REST BREATHING) INHALATION
Inhalation
Diaphragm contracts
External intercostals contract
Thoracic cavity expands
- lung volume increases
- lung pressure decreases
Inhalation (rest breathing)
Active muscle contraction
Diaphragm Contracts
Flatten goes down
External intercostals contract
small muscles that lay in between the rib cage, contracts and raises + forwards rib cage
Thoracic Cavity Expands
One goes up, the other goes down (pressure vs volume), boyle’s law
MUSCLE ACTIVITY FOR RESPIRATION (REST BREATHING) EXHALATION
Exhalation
Diaphragm relaxes
Elastic recoil of chest wall (external intercostals relax)
- RIB CAGE STARTS TO DESCEND
Lung volume decreases
Lung pressure increases
LUNG CAPACITY
can provide an index of pulmonary function
Differ according to age, sex, physical condition, physical activity
- REFERS TO HOW MUCH AIR OUR LUNGS CAN HOLD
How much cm h2o is required to generate our lungs in order to speak?
6-8cm h2o
How much cm h2o is required to get the vocal folds to open and vibrate?
3-4 cm h2o
SPIROMETRY
Vital capacity can be measured using spirometry (L)
REST BREATHING VS. SPEECH BREATHING
Speech breathing is a more complicated process than rest (vegetative) breathing:
- Need to take breaths at linguistically-appropriate places
- Need an appropriate amount of air to produce utterances (short/long) and support appropriate speech volume (conversational volume/loud volume)
SPEECH BREATHING
Major changes occur to switch from rest/vegetative breathing to speech breathing:
1. Location of air intake - primary use nose for resting, mouth for speech breathing
2. Inhale/exhale ratio time
- 10% is inhalation, 90% is exhalation
3. Volume of air inhaled per cycle
- take in more air when speaking
4. Muscle activity for exhalation
VOLUME OF AIR INHALED PER CYCLE
40% when resting, then changes to 60% = 20% change
For rest and speech breathing, the process of inspiration is …
the same (ACTIVE MUSCULAR PROCESS)
The process of expiration differs for rest and speech breathing
- Rest: Exhalation is passive, relying solely on elastic recoil forces
- Speech: The rate of elastic recoil forces must be controlled in order to prolong the expiration
Muscles of inspiration (external intercostals) continue to contract preventing the ribs from descending too quickly.
To go below EEL there is contraction in the abdominal musculature and the internal intercostal muscles
EEL MEANING
End expiratory level (EEL)
Vocal Fold Mucosa (Cover)
Epithelium and superficial lamina propria
Intermediate and deep layer of the lamina propria (Transition layers)
VIBRATES DURING PHONATION
Vocal Fold Body
Vocalis muscle, does not vibrate during phonation
MUCOSAL WAVE; how do the vocal folds move
Vocal folds open from back to front, bottom to top (anterior to posterior view)
anything that interferes with this routine results in rough voice, voice disorder
MYOELASTIC AERODYNAMIC EFFECT (vocal mechanics)
- medial compression
- subglottal (below vocal folds) pressure has to be higher than super glottal (above) pressure
- closing phase: passive breathing: elastic recoil of the muscle
- Bernoulli effect
- MEDIAL COMPRESSION
vocal folds come together at midline tightly
- SUBGLOTTAL PRESSURE
vocal folds blow open - opening phase
- CLOSING PHASE: ELASTIC RECOIL OF MUSCLE
vocal folds return to rest position
- BERNOULLI EFFECT
air coming from lungs and into vocal folds and moving quickly, sucks together
- - increase in velocity, decrease in pressure - -
VOICE DISORDERS
According to ASHA:
“A voice disorder occurs when a voice quality, pitch, and loudness differ or are inappropriate for an individual’s age, gender, cultural background, or geographic location.”
VOICE DISORDERS CATEGORIZED
Organic
- Structural
- Neurogenic
Structural
nerves are intact, but something is affecting the vocal folds
tumor that grows, changes how vocal folds vibrate
Neurogenic
one of the nerves that operates
vocal fold wraps around heart is damaged
vocal fold on left side doesn’t move - soft volume, out of breath
another: Parkinson’s disease
Functional
improper use of vocal mechanism (glottal fry)
HOW DO WE KNOW IF SOMEONE HAS A VOICE DISORDER?
Instrumental assessment (e.g. laryngeal imaging | acoustic analysis) Non-instrumental assessment (auditory-perceptual judgement)
auditory-perceptual judgement
just listening to their voice and seeing if there is a problem
- comes with a lot of listening experience, examples, sometimes
it is not accurate, depends on expertise and how much
time they’ve spent analyzing voice disorders
INSTRUMENTAL VOICE ASSESSMENT
Actually using equipment to look at laryngeal
-laryngeal imaging-
FLEXIBLE LARYNGOSCOPE (through nose), RIGID LARYNGOSCOPE (through mouth)
INSTRUMENTAL VOICE ASSESSMENT: ACOUSTIC ANALYSIS
Record patient
Task examples: sustained vowel, sentence, reading Analysis using software program (e.g. Praat, CSL)
Examples of acoustic parameters measured: Fundamental frequency (F0)
Formant frequencies (F1, F2)
Decibel level
Signal-to-noise ratio: above 20
Jitter - how stable frequency/pitch is
1.04% or lower NORMAL
- Shimmer: steady of amplitude (loudness)
lower than 3.8%
