Instrumental Assessment SPPA 6400 Voice Disorders: Tasko

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

Selected Instrumental Techniques Acoustic Analysis Aerodynamic Analysis Laryngeal Imaging SPPA 6400 Voice Disorders: Tasko

Acoustic Analysis of Voice SPPA 6400 Voice Disorders: Tasko

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

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

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

Voice Signal Typing SPPA 6400 Voice Disorders: Tasko Type I Type II Type III

Fundamental Frequency (F 0 ) Average F 0 speaking fundamental frequency (SFF) Correlate of pitch Infants – ~ Hz Boys & girls (3-10) – ~ 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

Intensity Average Intensity Correlate of loudness conversation: ~ dB SPL Intensity Variability  SPL to mark stress Contributes to prosody Measure – Standard deviation for neutral reading material: ~ 10 dB SPL

Perturbation Analysis Jitter: variability in the period of each successive cycle of vibration Shimmer: variability in the amplitude of each successive cycle of vibration …

Synthetic Continuum of Jitter SPPA 6400 Voice Disorders 0.0%2.0% 0.2%2.5% 0.4%3.0% 0.6%4.0% 0.8%5.0% 1.0%6.0% 1.5%

Harmonic peak Noise ‘floor’ Frequency Amplitude Harmonic peak Harmonics-to-noise Ratio

Cepstral Based Measures

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

Voice Range Profile SPPA 6400 Voice Disorders: Tasko

Aerodynamic Analysis of Voice SPPA 6400 Voice Disorders: Tasko

Aerodynamic Testing SPPA 6400 Voice Disorders: Tasko

Aerodynamic Testing SPPA 6400 Voice Disorders: Tasko

Aerodynamic Testing Average Flow Rate Typical values ml/sec Hyperfunction associated with lower values Hypofunction associated with higher values Subglottal Pressure Typical values 5-8 cm H20 Phonation Threshold Pressure (PTP) Minimum pressure needed to initiate phonation Typical values 3-5 cm H20 Laryngeal Airway Resistance (LAR) subglottal pressure/mean flow rate Estimates the resistance at level of the larynx SPPA 6400 Voice Disorders: Tasko

Laryngeal Imaging SPPA 6400 Voice Disorders: Tasko

SPPA 6400 Voice Disorders Laryngeal Imaging Direct Laryngoscopy Indirect Laryngoscopy – Mirror examination – Rigid laryngeal endoscopy Constant light Stroboscopy – Flexible fiberoptic laryngeal endoscopy Constant light Stroboscopy

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

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

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

Gross Observations Glottic Closure Supraglottic hyperfunction Mucus General Appearance Mobility SPPA 6400 Voice Disorders: Tasko

SPPA 6400 Voice Disorders Stroboscopic observations Glottic Closure Phase Closure Symmetry Amplitude Mucosal wave Stiffness/nonvibrating portion/adynamic segment Periodicity

SPPA 6400 Voice Disorders Example of a VLS evaluation form