1 Acoustic Phonetics 3/28/00

2 Nasal Consonants Produced with nasal radiation of acoustic energy Sound energy is transmitted through the nasal cavity Primary acoustic cues: –Murmur –Formant transitions

3 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

4 Spectrogram: Nasals Nasal Murmur mnaa

5 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)

6 Spectrum: Changing Pattern of Fricative Noise

7 Spectrogram: Fricatives Higher energy spectraLow to mid energy spectra

8 Spectrogram: /thief/ spoken by a woman th ie f Similar frication pattern between /th/ & /f/

9 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

10 Spectrogram: /judge/

11 Glides Semivowels /j, w/ Gradual transitions that appear on the spectrogram as a slowly changing formant pattern –Formant transitions: Duration= ms

12 Spectrogram: Glides

13 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

14 Spectrogram: Liquids r l

15 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