Basic Spectrogram & Clinical
Application: Consonants
Sonarants
• Consonant that manipulates vocal tract
resonance
• Characteristics
– F2 & F3 formant changes
– Transitions
• Include:
– Nasals /m/, /n/ & /h/
– Liquids /r/, /l/
– Glides /w/, /j/
Sonorants
• Production involves a greater constriction
when compared to vowels and a quicker
more extreme movement of the vocal tract
compared to diphthongs
• Movements and formant transitions slower
than all other consonants
Nasals
• Low frequency energy (near Fundamental
Frequency)- Nasal Murmer
• Place of nasal articulation is defined by the
2nd formant transition & place of
antiresonances
m
a
Nasal Murmur
Spectrogram: Nasals
n
a
Glides
• Semivowels /j, w/
• Gradual transitions that appear on the
spectrogram as a slowly changing
formant pattern
– Formant transitions:
• Duration= 75-150 ms
Spectrogram: Glides
Liquids
• Liquids /l, r/
• Formant pattern steady state and transition
is the primary acoustic cue
– Prolongation effects
• /l/ steady state formants
– F1= 360 Hz
– F2= 1300 Hz
– F3= 2700 Hz
• /r/ steady state formants
– Same F1 & F2 as /l/ but much lower F3
Spectrogram: Liquids
r
l
Stops
– Acoustic Cues: Silent or low energy interval,
burst, transition
• Silent interval = oral constriction (I.e. closure of lips
for /b/); also termed a stop gap
– Voiced stops can be seen on the voice bar as noise energy
• Burst = Articulatory constriction is released; energy
released looks like noise on the spectogram
• Transition= formant transition into following vowel
Stops
• Bilabial Stops (/p/, /b/):
– F1 starts at zero & rises to F1 of next vowel
– F2 starts at 800 Hz & rises to F2 of following vowel
– F3 increases for following vowel
• Alveolar Stops (/t/, /d/):
– F1 same as for bilabial stops
– F2 starts at 1800 Hz & rises to F2 of following vowel
• Velar Stops (/k/, /g/):
– F1 same as for bilabials
– F2 has 2 starting points 1300 & 2300 Hz
Spectrogram with Transitions: /d a d/
Voiceless Stop Consonants
Stops
• Characteristics:
– Voice onset time (VOT)= time between stop
release (burst) and the onset of glottal pulsing
• Voiced= shorter VOT
• Longer VOT in cleft palate, dysarthric speakers and
phonological disorders
Fricatives
• Spectrum of noise is the acoustic cue & formant transition
• Specific location of turbulence
– Labiodental /f,v/
• Low energy, flat diffuse spectra (front cavity is short with little
filtering effect on noise energy)
– Linguadental /q,ð/
• Low energy, flat and diffuse spectra (front cavity gives little shaping
to spectrum)
– Lingu-alveolar /s, z/
• High energy noise spectra, energy lying in high frequencies (above 4
kHz) (front cavity longer contributing to distinctive spectral shaping)
– Linguapalatal /sh, zh/
• Intense noise spectra, energy lying in mid to high frequencies
(above 2kHz) (front cavity significant resonance effect)
Spectrum: Changing Pattern of Fricative
Noise
Fricatives: Spectrum
Higher energy spectra
Low to mid energy spectra
Affricates
• Affricate consonants have a stop gap
(silence, low energy interval) followed
by intense frication
– Stop gap= articulatory closure
– Frication= noise after closure is
released
Spectrogram: /judge/
Laboratory
• Part I: SONORANTS:
– Nasal Consonants
• Make a wide-band spectrogram of:
• “mow”, “no”
– Draw a vertical line where consonant ends and vowel
begins
– Locate nasal murmer, 1st & 2nd formants, antiresonances
– What spectral differences do you see?
– Locate the 2nd formant transitions on both. What are the
differences?
• “Some”, “Sun”
– Label the same as the first spectrogram
• Contrast both spectrograms
Laboratory
• Part II: Approximants
– Glides & Liquids
• Wide band spectrogram of “a ray”, “a lay”, “a way”,
“a yea”
• Label each phone on the spectrogram
• Compare /r/ & /l/
• Determine the relative frequency of F1, F2 & F3
• Determine whether there is acoustic energy
present at higher frequencies is low or high
• What acoustic characteristics are different
between consonants?
Laboratory
• Part III: Silibants
– Fricatives
• Say “sigh” and “shy” at a moderate rate
• Obtain a wide-band spectrogram (at least 8
kHz)
• Locate & label each phone
• What are the spectral characteristics that
distinguish it from vowels and other
consonants?
Laboratory
• Part II: Nonsilibnts
– Obtain a wide-band spectrogram of “high”, “fie” and “thigh”
• Label each phone
• What spectral features distinguish phones?
• How do they differ from silibants?
– Obtain a wide-band spectrogram of “ether” and “either”
– Label