Chapter 6: Instrumental Measure of Voice Flashcards
Treatment outcomes measures need to be _____________, _______, ______________, and ____________ to heterogeneous voice qualities and severities.
objective
valid
automated
sensitive
What are 5 types of instrumental measures of voice?
1) acoustic recording and analyses
2) aerodynamic measurement
3) laryngeal imaging
4) electroglottography (EGG) (measures VF contact area)
5) laryngeal electromyography (LEMG) (direct measures of muscle activity)
What are the 3 basic types of technical instruments?
1) signal detection
2) signal manipulation or conditioning
3) signal reconversion
What 4 technical instruments are used for signal detection?
1) microphone
2) camera
3) electrode
4) flow/pressure transducers
What 3 technical instruments are used for signal manipulation or conditioning?
1) filtering
2) amplification
3) digitization
What 3 technical instruments are used for signal reconversion?
1) numerical form
2) visual display
3) speaker
Acoustic measurements can provide ____________ and ________________ analysis of vocal function
objective
noninvasive
Clinical utility of acoustic measures depends upon whether the acoustic measures: (3)
1) can discriminate between normal and disordered voices
2) correlate with auditory-perceptual judgements of voice quality and severity
3) sufficiently stable to assess real change in performance across time
Most acoustic measures are mathematical derivations of 5 common measures:
1) fundamental frequency
2) intensity
3) perturbation measures
4) ratio of signal (i.e. harmonic) energy to noise
5) spectral or cepstral features
What is fundamental frequency?
rate of vibration of the vocal folds expressing in Hz or CPS
What is the perceptual correlate of F0?
pitch
What are 2 clinical measures related to fundamental frequency?
1) mean F0 (for connected speech vs. sustained vowels)
2) F0 range (highest and lowest pitch a patient can produce)
What is the acoustic correlate of vocal loudness?
vocal intensity
Intensity is referenced to _________ ___________ __________ (___) and measured on a _______________ _________ (__) scale
sound pressure level (SPL) logarithmic decibel (dB)
What two measures of intensity are clinically useful?
1) habitual intensity
2) intensity range (min and max)
What are 3 potential instruments for measuring intensity?
1) sound level meters
2) acoustic analysis programs
3) aerodynamic measurement devices
What does frequency-intensity profiling give a thorough description of?
patient’s physiologic limits of frequency and intensity
How do you do frequency-intensity profiling? (3)
1) voice range profile
2) phonautogram
3) physiologic frequency range of phonation
What are the two major types of voice acoustic analysis?
1) time-based measures
2) frequency-based measures
What are time based measures of voice?
perturbation measures such as jitter and shimmer
What are frequency based measures of voice?
spectral and cepstral
What is perturbation?
cycle-to-cycle variability in a signal
What voice production is typically used to measure perturbation?
sustained vowel production
What is jitter?
cycle-to-cycle variability in frequency
What is shimmer?
cycle-to-cycle variability in amplitude
Calculation of perturbation measures requires a ________________ (aka Type I) signal for realizable/valid analysis
quasi-periodic
What is a signal(harmonic)-to-noise ratio?
ratio of periodic/harmonic signal energy to aperiodic/noise energy in the voice waveform
What is the SNR for normal voices?
mostly periodic and high signal/harmonic energy, high SNR/HNR
What is the SNR for dysphonic voices like?
increased aperiodic/noisy components (roughness, breathiness, turbulent), thus “low” SNR or HNR
What are the 2 limitations of time-based perturbation measures?
1) depends on accurate identification of cycle boundaries, so results become questionable in moderate to highly perturbed voice signals
2) time-based measures are based on assumption of relatively steady pitch and loudness (sustained vowels)
In contrast to tradition time-based analysis, spectral-based acoustic measures have the ability to characterize the voice signal by extracting characteristics such as the __________________ _______________ and the relative ___________ of ______________ versus ____________ without needing to identify cycle boundaries.
fundamental frequency
amplitude of harmonics vs. noise
The spectral-cepstral analysis methods analyzes ___________ of data rather than __________
frames
cycles
What does spectral analysis assess?
the interaction between glottal sound source (VFs) and the supraglottic (vocal tract) influences