Ways to Assess the Utility of Instrumentation Does it help
detect the existence of a voice problem? Can it help establish the
severity of progression of a voice problem? Can it help
differentially diagnose a voice problem? Can it be used as a
treatment tool, in the form of biofeedback, behavioral modification
or patient education? SPPA 6400 Voice Disorders: Tasko
Acoustic Analysis of Voice SPPA 6400 Voice Disorders:
Tasko
Slide 6
Recording Considerations Equipment Microphone and preamplifier
setup Handheld, headset, dynamic mic, condenser mic Device onto
which signal is recorded Computer, dedicated recording device
Optimizing Recording Microphone Position Recording levels
Digital-to-audio conversion settings SPPA 6400 Voice Disorders:
Tasko
Slide 7
SPPA 6400 Voice Disorders Analysis Considerations Real-time
analysis Examples Sound level meter Visi-pitch Real-time
spectrograms Off-line analysis (analysis after data is collected)
Examples Computerized speech Lab (CSL), MDVP Cspeech (tf32) Praat
Speech Tool
Slide 8
Voice Signal Typing Type I Quasiperiodic, continuous signal
Single cluster of dominant F0 values F0 and traditional
perturbation analysis can be used. Type II Random or periodic
modulations that fluctuate too much to detect a single recurring
F0. Analysis limited to spectral analysis. Type III Random
aperiodic signals with no identifiable fundamental frequency
whatsoever. Not appropriate for most acoustic analysis. SPPA 6400
Voice Disorders: Tasko
Slide 9
Voice Signal Typing SPPA 6400 Voice Disorders: Tasko Type I
Type II Type III
Slide 10
Fundamental Frequency (F 0 ) Average F 0 speaking fundamental
frequency (SFF) Correlate of pitch Infants ~350-500 Hz Boys &
girls (3-10) ~ 270-300 Hz Young adult females ~ 200 Hz Young adult
males ~ 120 Hz Older females: F 0 Older males: F 0 F 0 variability
F 0 varies due to Syllabic & emphatic stress Syntactic and
semantic factors Phonetics factors (in some languages) Provides a
melody (prosody) Measures F 0 Standard deviation ~2-4 semitones for
normal speakers F 0 Range maximum F 0 minimum F 0 within a speaking
task
Slide 11
Intensity Average Intensity Correlate of loudness conversation:
~ 65-80 dB SPL Intensity Variability SPL to mark stress Contributes
to prosody Measure Standard deviation for neutral reading material:
~ 10 dB SPL
Slide 12
Perturbation Analysis Jitter: variability in the period of each
successive cycle of vibration Shimmer: variability in the amplitude
of each successive cycle of vibration
Harmonic peak Noise floor Frequency Amplitude Harmonic peak
Harmonics-to-noise Ratio
Slide 15
Cepstral Based Measures
Slide 16
SPPA 6400 Voice Disorders Other acoustic measures Maximum
Phonational Frequency Range Highest F0 - Lowest F0 Dynamic range
Highest intensity lowest intensity Voice Range Profile/Phonetogram
Dynamic range from lowest to highest F0
Slide 17
Voice Range Profile SPPA 6400 Voice Disorders: Tasko
Slide 18
Aerodynamic Analysis of Voice SPPA 6400 Voice Disorders:
Tasko
SPPA 6400 Voice Disorders Components Endoscope (rigid or
flexible) Light source (constant or strobe) Camera Recording device
(VHS, computer) If strobe light is used, a neck mounted microphone
(or electroglottograph) is used for tracking F o
Slide 25
SPPA 6400 Voice Disorders Constant light vs. strobe light
Constant light source allows viewing of basic structure and
function Identify lesions Identify abnormalities in ab/adduction
Identify supraglottic activity Strobe light source allows a view of
simulated vibration allows assessment of the vibratory function of
the vocal folds May reveal structural abnormalities not seen during
constant light endoscopy
Slide 26
SPPA 6400 Voice Disorders Typical VLS Examination A task list
Normal, loud and soft phonation Pitch glide (glissando) Laryngeal
diadochokinesis - /i i i/ /hi hi hi/ Cough Normal & deep
breathing
