Terms:

Bernoulli effect:  demonstrates that air flowing rapidly through a narrow space that causes a negative drop in pressure

Cover-body theory: states that the vocal fold has layers of different stiffness that account for vocal fold vibration or mucosal wave

damping:  loss of amplitude.

declination view of intonation:  theory of sentence intonation that describes the pattern of f0 across an utterance as steadily falling off in frequency.

diadochokinetic rate: The rate at which a speaker can alternate simple syllables such as /pa/, /ta/, /ka/

electroglottograpy (EEG):  one type of recording specific to laryngeal measures; measures rate of vocal fold vibration.

electromyography (EMG):  a procedure in which electrodes are affixed to patient’s skin, or inserted into muscle, to measure muscle activity.

electropalatography (EPG):  a procedure in which a plate with sensing electrodes is used to measure contact of the tongue with the hard and soft palate.

formant frequency (formant):  frequency component amplified by resonator (vocal tract).  Acoustic properties that distinguish speech sounds.  Maxima of harmonic energy.  Although revealed by a Fourier analysis, typically measured by LPC or spectrographic analysis.

formant transition:  change in frequency value of formant over time; reflects change in position of articulators.

Fourrier analysis: analyzing a complex wave into its componet frequencies

fundamental frequency: number of cycles of  vocal fold vibrations in one second

harmonics:  product of vocal folds; fundamental frequency and multiples.

intonation:  prosody component of speech; fluctuation of fundamental frequency across the sentence domain.

intraoral pressure:  air pressure within oral cavity (mouth).

Jitter: frequency pertubation

linear predictive coding (LPC):  mathematical algorithm that determines precise formant frequency values.

manometer: measures long-term intraoral breath pressure

periodic: repeating in a regular fashion

phonation threshold: minimum pressure required to set the folds into vibration

plethysmograph: measures lung volume changes during speech by measuring changes in the thoracic and abdominal volumes

pneumotachograph: measures respiration investigating changes in glottal airflow

resonance:  vibration of a body of air caused by a sound source; in speech the vocal tract is an acoustic resonator that modifies the harmonics of the vocal fold, the source of sound.

shimmer: measures period to period amplitude variations

source-filter theory:  theory of speech production denoting the vocal folds as one source of sound and the vocal tract as the filter, modifier of that sound source.

Spectrum: an analysis of the sound energy in terms of the magnitude of its frequency components.
Spectrum of the sounds source:
    a.  Fundamental frequency
    b.  multiples/harmonics of the fundamental frequency (harmonics diminish in intensity as they increase in frequency.)
The harmonics of the glottal sound wave which are at or near the spectral peaks of the transfer function of the vocal tract are resonated and those distant from the resonant frequencies of the tract loose energy and are thus greatly attenuated.

The sound that emerges at the end of the tract has the same harmonics as the sound at the source (glottis) but the amplitudesof the harmonics have been modified, altering the quality of the sound.  Andy change of the vocal tract configuration alters the frequencies at which the cavities resonate.   Altered cavity sizes resonate at different frequencies.  The sound that emerges from the lips is a product of the sound of the vocal fold vibration (source function) and the resonances of a particular vocal tract shape and length (the transfer function) plus an effect of sound radiation at the lips.

Spectrogram: depicts the formants of the vocal tract as broad bands of energy.  The frequency of a formant is measured at the center of the band of energy.  This frequency may or may not correspond to the frequency of one of the harmonics.
Wide band verses spectra output (narrow band)
The spectrogram shows frequency changes in time.
The spectrum show the amplitude of the component frequencies or harmonics.
    a.  Sectrum Output: instantaneous respresentation of the vowel
    b.  Spectrogram depicts peaks of resonance as they change over time.
Wideband output provides no information about the frequencies of the individual harmonics that compose the resonance peaks.  The center frequencies of the formants (resonance peaks) are of interest.

spectrograph:  machine that produces spectragrams.

spectragram:  visual image of speech measuring frequency by time; amplitude is noted in the shading of the spectrogram.

spirometer: measures airflow volumes and capacities

strain gage: measures recording lip and jaw displacement

steady state formant:  acoustic characteristic of vowels, seen on spectragrams as unchanging (horizontal) formants across the full segment.

stress:  prosodic component conveyed by the combination of amplitude, duration, and frequency fluctuations; can convey information about word meaning, sentence emphasis, or emotional state of speaker.

stroboscopy: permits viewing of the vocal folds in slow motion

subglottal:  below the glottis (vocal folds).

voice onset time (VOT):  time between the release of a stop consonant and the start of phonation; longer VOT values are associated with English voiceless stops while shorter VOT values are associated with English voiced stops.

waveform:  visual representation of speech displaying amplitude by time.