Chapter 6: Acoustic Characteristics of Vowels and Consonants Flashcards
(22 cards)
Three major physical parameter used to describe acoustic characteristics of any sound
-time
-frequency
-intensity
Time
-duration of a sound
-measure in msec or sec
-1 sec = 1000ms
Frequency
-number of cycles of vibration
-measure in hertz (cycles per second)
-pitch: perception of frequency
Intensity
-magnitude of energy associated with a sound
-measured in decibels (dB)
-loudness: perception of intensity
Waveform
-amplitude as a function of time
-x-axis: time
-y-axis: intensity
Intensity Contour
-average intensity as a function of time
-x-axis: time
-y-axis: intensity
Spectrogram
-intensity and frequency as a function of time
-x-axis: time
-y-axis: intensity
-gradients in shading: intensity
Vowels vs Consonants
-greater amplitude than consonants
-longer in duration than consonants
Formants
-dark bars shown on spectrograms that identify vowels
-formants are resonant frequencies of the vocal tract
Spectrum
-the frequency array, or energy pattern, associated with any sound
-vowel production is associated with low-frequency energy
-vowels are considered to have low-frequency spectra
Energy of Vowels
low-frequency energy
VOT: Voice Onset Time
-the time between the release of the stop burst and the onset of the voicing of the vowel
Prevoicing
-onset of voicing occurs before release burst in stops
-negative value
Voiceless Fricatives
-voiceless fricatives have greater airflow through the constriction
Formant Transition
Formant changes as vocal tract shape changes
Damping
-nasals
-reduction in amplitude of a vibrating system.
-nasal cavity absorbs acoustic energy from vocal tract, making vocal tract resonances weaker
Nasal Murmur
sound created when VP is open, sound is radiating through nasal cavity
Antiformats
negative resonances of the vocal tract
Clinical Application of Acoustic Analysis
-used to evaluate effect of speech therapy on transgender speech
-used to verify the presence/absence of speech sounds, phonological processes, and hypernasality
-can be used in evaluation of individuals with neurological disease and development of speech production
Resonances are determined by
-specific tongue and jaw positions unique to each vowel
Voice Bar
-Dark band on spectrogram demonstrating sound energy associated with voicing
Acoustic Characteristics Consonants vs Vowels
-voicing: all vowels are voiced, consonants can be voiced or voiceless
-manner: vowels are produced with a relatively unobstructed vocal tract, consonants produced with a relatively obstructed vocal tract
-resonances: vowel resonance determined by tongue position, consonant resonance determined by sound source, how airflow is modified, and the point of obstruction
