SHH 382: Exam 3

Transglottal pressure differential

pressure below and above the vocal folds

Waveform horizontal axis

time (msec/sec); duration of acoustic signal

Waveform vertical axis

amplitude (intensity of acoustic signal

Spectrum horizontal axis

frequency (Hz)

Spectrum vertical axis

amplitude (dB)

Waveform

shows amplitude changes overtime

Spectrum

shows the amplitudes of frequencies present in one moment in time

Spectrogram

shows all three sound signal characteristics; durarion, frequency, and amplitude (darker the area the louder the signal, higher frequency has lighter amplitude)

Source-filter theory of vowel production

explains how the vocal tract filters the glottal sound wave to generate different vowels (monopthongs, dipthongs)

Glottal source spectrum

vibration of the vocal folds, source function

Filter

vocal tract resonance curve, transfer function

Speech sound

filtered glottal sound, output function

Glottal source spectrum

complex periodic sound produced by the vibrating vocal folds

Natural frequency

the frequency at which an object vibrates freely and is determined by the object’s physical characteristics (length, stiffness)

Formants

resonant frequencies of the vocal tract; amplified harmonic bands

Filter curve

shapes amplitude for that sound

Overtune

natural harmonic that is present everytime you sing a note

Formant frequencies

reflect resonance characteristics of the vocal tract, change when the position of one or more articulators changes

Formant 1 (F1)

related primarily to tongue height or oral opening (the more opening, the higher F1)

Formant 2 (F2)

related primarily to tongue advancement (the more advanced the tongue position, the higher F2)

Spectrogram: acoustic characteristics of monopthongs

a sustained vowel has a constant formant pattern, different vowels have different formant patterns

Spectrogram: acoustic characteristics of dipthongs

change in the frequencies of F1 and F2, when a formant changes it’s direction

Stop gap

time interval from offset of vocal fold vibration preceding a stop consonant to release of the articulatory obstruction for that consonant

Voice onset time

time interval from release of the obstruction for a stop consonant for that consonant

Anti-formants

reduced energy