1 acoustic phonetics 3/28/00. 2 nasal consonants produced with nasal radiation of acoustic energy...

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Acoustic Phonetics

3/28/00

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Nasal Consonants• Produced with nasal radiation of acoustic

energy• Sound energy is transmitted through the

nasal cavity• Primary acoustic cues:–Murmur– Formant transitions

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Nasal Consonants• Murmur:– Low frequency energy– Low frequency resonance below 0.5 Hz– Three nasal consonants have similar but not exact

murmur patterns• Place of production relies on formant transitions

– Most productive as a manner cue– Antiformant production• Result in loss of acoustic energy because of damping in

the nasal cavity

4Spectrogram: Nasals

Nasal Murmurm na a

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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 /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)

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Spectrum: Changing Pattern of Fricative Noise

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Spectrogram: Fricatives

Higher energy spectra Low to mid energy spectra

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Spectrogram: /thief/ spoken by a woman

th ie f

Similar frication pattern between /th/ & /f/

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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

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Spectrogram: /judge/

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Glides

• Semivowels /j, w/

• Gradual transitions that appear on the spectrogram as a slowly changing formant pattern– Formant transitions:• Duration= 75-150 ms

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Spectrogram: Glides

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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

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Spectrogram: Liquids

r l

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Phonetic Quality: Suprasegmentals• Speech also consists of properties:– Speaking rate– Pitch– Intonation– Stress– Rhythm

• The influence of suprasegmentals extends beyond the boundaries of individual phonetic elements