formant frequencies and spectrograms Flashcards
how are vowels categorized?
vowels are characterized by different patterns of formants and different qualities
what do formant frequencies depend on?
the length of an individual’s VT
format frequencies are lower/higher for…
lower for adult men and higher for women
formant frequencies for /a/ (hot)
F1=730 F2=1090 F3=2440
forman frequencies for /iy/ (beet)
F1=270 F2=2290 F3=3010
what is a spectrogram?
a visualization of a sound or sounds over time in terms of the amount of acoustic energy at different frequencies
spectrograms show…
frequency (on vertical axis), amplitude (represented by darkness), and time (bottom axis)!
what are resonant sounds?
vowels, diphthongs, glides, liquids, and nasals
obstruents
non resonant sounds (constriction is present in VT)
diphthongs
combination of 2 vowels, where formant transitions are slow
the formant transitions in diphthongs represent…
the change on tongue position, which also changes resonant frequencies
glides
quick and smooth vowel transitions from front to back tongue position or vice versa
- no steady state, only transitions
ex) j (eeya)
what are diphthongs and glides both characterized by?
FORMANT TRANSITIONS which are changes in the formant frequencies that occur as the VT resonance changes during the sound
spectrographic characteristics of stops include
silent gap, release burst, and voice onset time
voiceless stops are
complex aperiodic (P, T, K, and glottal)
voiced stops are
periodic and aperiodic (B, D, G)
how are stops articulated?
1) there is a buildup of oral pressure because the VT is sealed off with complete constriction of the articulators
2) release of pressure
which articulator may be constricted during a stop
lips, glottis, velar, and alveolar ridge
what does a voiceless stop look like on a spectrogram?
THIN vertical line- because of its short duration and it covers a broad range of frequencies
only release burst is shown, pressure build up is a silent gap in time.
what does a voiced stop look like on a spectrogram?
same as voiceless stop, but because the vocal folds vibrate, its also periodic, which means there is a Fo, harmonics, and formants.
Fo=voice bar (lowest frequency)
F1= formant 1
F2= formant 2
F3= formant 3
what does fundamental frequency reflect?
vocal FOLD vibration/pitch
what do formant frequencies reflect?
the vocal TRACT, formants change the quality of a sound
aspiration
noise generated by turbulent airflow (released pressure)
there is more aspiration generated during…
voiceless stops
how are fricatives produced?
1) a narrow channel is created by articulators for air to flow through
2) air is forced through the channel and makes an aperiodic sound when voiceless and aperiodic and periodic when voiced
frication
the result of turbulent airflow in a fricative and is dipicted as a winde band of energy distributed over a broad range of frequencies
how are voiceless fricatives shown on a spectrogram?
THICK vertical lines that cover a broad range of frequencies
fricatives are continuous vs. stops which are transient
how are voiced fricatives shown on a spectrogram?
same as voiceless with voice bar and formants
affricates
are continuous also, they are a stop + fricative
how are nasals produced?
1) block air from exiting oral cavity (velum is lowered, full blockage in oral cavity)
2) air exits nasal cavity
nasal formant
an additional high energy low frequency formant because of nasal cavity
antiformants
areas of REDUCED acoustic energy
why do antiformants occur?
because air in the oral cavity is trapped and acts as a band stop filter, which means it resonates frequencies outside of its bandwidth and damps those within.
coarticulation
occurs when articulators move almost simultaneously in the production of adjacent sounds
the acoustic characteristics of the upcoming sound influence the preceding sound
the acoustic characteristics of the preceding sound influence the following sound
ex) Ki Ku
dim did
liquids
not turbulent. mostly laminar
no formant transitions! look like vowels on spectrograms
suprasegmentals
intonation and stress!
intonation
variation in Fo levels throughout utterance
rise fall
fall rise
stress
relative emphasis on a syllable or a word
