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A single acoustic goal of / sh / (rel. to /s/) and 3+1 vocal-tract models. Martine TODA & Shinji MAEDA. Presented at ASPI Stockholm meeting, 04/07/2006. Average acoustic contrast between /s/ and / sh / in French (7 speakers). Acoustic goal for / s /:
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A single acoustic goal of /sh/ (rel. to /s/) and 3+1 vocal-tract models Martine TODA & Shinji MAEDA Presented at ASPI Stockholm meeting, 04/07/2006
Average acoustic contrastbetween /s/ and /sh/ in French (7 speakers) Acoustic goal for /s/: To maximize power at 8 kHz and to reduce power in lower frequencies Acoustic goal for /sh/: To maximize powder at 4 kHz and to reduce power in higher frequencies Power differences /sh/- /s/ (dB) Standard deviation Average difference 4 kHz 8 kHz Frequency (Hz)
4.5 cm; 30 sagittal slices 12.8 cm x 12.8 cm; 512 x 512 pixels tissues Articulatory data TE : 3.3 ms TR : 10 ms Duration : 23 s Antenna : high resolution ‘neck coil’, positioned in front of the lips (7 native French speakers) MRI data acquisition and insertion of numerical teeth casts Shimadzu-Marconi Eclipse 1.5T • Tasks: • Sustained /s/ • Sustained /sh/ • Teeth: lips and tongue put tightly close to the teeth
/sh/ palatalized w.r.t. /s/ lips velum Two articulatory strategies in /sh/ vs. /s/ of French a. Tongue « position » strategy b. Tongue « shape » strategy or ‘[c]-like’ /sh/ J V1 Sagittal contour tracings from MRI /s/ Protrusion /sh/ Palatal channel (tube) of /sh/ : about 5 cm Aligned at the maximal constriction Front oral cavity of /sh/ Area function estimated from MRI Sublingual cavity of /sh/ /s/ /sh/
Front cavity resonance Front cavity + side branch resonance Front cavity (+SB) free zero Acoustic models of /sh/ a. « position » strategy b. « shape » strategy single peak fill-up J V1 Natural spectra (/sh/) 2 peaks 2 cm i) front cavity model * glottis lips iii) palatal tube model Equivalent 1D models or 2 cm 1 cm 5 cm * 1 cm 0.5 cm2 2 cm2 * ii) side branch model 2 peaks = acous. coupling Calculated Transfer functions Pole-zero pair of the palatal tube Front cavity resonance Front cavity free zero
Source in the front cavity Source in the palatal channel Effect of source location in palatalized /sh/ Front cavity resonance 1st palatal channel resonance 2nd resonance of palatal channel iii) palatal tube model * * 2 cm 5 cm vi) paratal tube+source model Pole-zero pair of the palatal channel -15 dB offset
P Fr. Speaker-2 (J): Type ii model, position “Side-branch”
Protrusion Fr. speaker-1 (D): Type i model, position /s/ // “Front-tube”
Fr. Speaker-7 (Y): Type i model, position “Front-tube”
P Fr. Speaker-4 (S2): Type iii model, position “Side-branch” “coupled palatal-tube” “no palatal noise source”
“coupled palatal-tube” “palatal noise source” Fr. Speaker-3 (S1): Type iv model, shape
Fr. Speaker-5 (V1): Type iv model, shape “coupled palatal-tube” “palatal noise source”