3 Features of nasals Vocal tract longer than for oral sounds ↓ resonant (formant) frequenciesNasal formant/murmurNasal cavity is acoustically absorbentAttenuates overall energyActs as a low-pass filterPharyngeal/oral cavity acts as a “cul-de-sac”Introduces antiresonances/antiformantsFormant transitionsVaries for place of articulation
9 Silent gap/closure interval voicelessWhat is it?Period during VT occlusionVoiceless:relatively longVoiced:reduced or absent closure intervalMay exhibit a “voice bar”voicedvoice bar
10 How can voicing continue with a closed vocal tract? QuestionHow can voicing continue with a closed vocal tract?
11 Release burst What is it? Acoustic energy associated with VT release Transient:~10-30 msecAperiodicOften absent in final position
12 Release burst Provides place information Spectral shape related to cavity size in front of constrictionBilabial:diffuse energy dominant in low frequencyEither gently sloping spectrum or ~ HzAlveolar:diffuse energy that is dominant in higher frequencies (>4000 Hz)Velar:compact energy in midrange ( Hz)
13 Aspiration Observed in voiceless stops Consequence of air turbulence at the open glottisIncreases the duration of the release burst
14 Voice onset time voiceless voiced Voiceless Termed long lag VOT VOT ranges from 25 – 100 msecVoicedShort lag:Voice onset shortly after releaseVOT>0Simultaneous voicing:voicing and release are coincidentVOT = 0Prevoicing/VOT lead:voicing occurs before releaseVOT <0VOT ranges from –20 – 20 msecvoiced
15 Voice onset time VOT may distinguish place of articulation Bilabial: relatively short VOTAlveolar: mid-length VOTVelar: relatively long VOTRULE: as the cavity in front of the occlusion gets longer, VOT increases
17 Voice onset time has been considered an important measure of coordination. Why?
18 Formant TransitionsFormants of adjacent vowels will change with VT occlusionTransitions will last about 50 msec (shorter than glides/liquids)Transitions not obvious with voicelessThe form of the transition is a function ofThe place of articulationThe neighboring soundF1 and F2 are the key players