University of Silesia Acoustic cues for studying dental fricatives in foreign-language speech Arkadiusz Rojczyk Institute of English, University of Silesia University of Silesia

Interdanetal fricaives are difficult for Polish learners BACKGRUND Interdanetal fricaives are difficult for Polish learners Neighbouring Polish fricatives: /s/ and /f/ English voiceless interdental fricatives can be substituted by Polish /s/, /f/ or /t/ Perceptually /Ɵ/ is most often confused with /f/ by native and L2 listeners (Brannen 2002; Cutler et al. 2004) University of Silesia

L2 speech research on production of interdental fricatives BACKGRUND L2 speech research on production of interdental fricatives is often based on auditory identification The need for reliable spectral cues for L2-speech research Simplicity of measurement procedures Previous studies - interdental fricatives in native speech (e.g. Jongman et al. 2000) - compare interdental fricatives in native and L2 speech (Hanulikova and Weber 2010) The need for comparing sound categories within one system (eliminating physiological variability) University of Silesia

overall noise intensity F2 onset of the following vowel TESTED CUES spectral peak overall noise intensity F2 onset of the following vowel F2 transitions into the following vowel centre of gravity root mean square (RMS) amplitude in Pa University of Silesia

29 advanced learners of English PARTICIPANTS 29 advanced learners of English Institute of English, University of Silesia 22 females, 7 males courses in English pronunciation University of Silesia

flanked by vowels /a/, /i/, /u/ afa atha asa ifi ithi isi ufu uthu usu MATERIALS voiceless /f/, /Ɵ/, /s/ flanked by vowels /a/, /i/, /u/ afa atha asa ifi ithi isi ufu uthu usu University of Silesia

Acoustic laboratory, Institute of English, University of Silesia RECORDING Acoustic laboratory, Institute of English, University of Silesia sound-proof booth Headset dynamic Sennheiser HME 26-600 10 cm away, 45-deg angle Preamp: USBPre 2, wav file Sampling: 22 kHz; 16 bit High-pass filtered 0-200 Hz University of Silesia

30 advanced leaners of English, University of Silesia IDENTIFICATION 30 advanced leaners of English, University of Silesia identification task (Praat script): identify the consonant as /f/, /Ɵ/ or /s/ 29 speakers x 9 tokens x 1 repetition = 261 stimuli Purpose: find speakers who consistently produce all tested fricatives as identifiably separate categories 12 speakers selected (10 females; 2 males) University of Silesia

spectral peak: 40-ms Hamming window MEASUREMENTS spectral peak: 40-ms Hamming window overall noise intensity: the whole frication portion F2 onset and transitions: downsampled to 1 kHz, LPC order 12 centre of gravity: power = 1.0 RMS amplitude: the whole frication portion measurements: 12 speakers x 9 tokens x 6 cues = 648 Praat, Akustyk University of Silesia

Repeated-measures ANOVA 3 (/f/, /Ɵ/, /s/) x 3 (/a/, /i/, /u/) ANALYSIS Repeated-measures ANOVA 3 (/f/, /Ɵ/, /s/) x 3 (/a/, /i/, /u/) Post-Hoc: Bonferroni University of Silesia

A completely unreliable cue RESULTS Spectral peak A completely unreliable cue University of Silesia

Overall noise intensity RESULTS Overall noise intensity Main effect (consonant): F(2, 22) = 33,753, p<,01** No difference between /f/ and /Ɵ/: Bonferroni p>,05 No consonant x vowel interaction: F(4,44) = 2,501, p>,05 University of Silesia

L2 onset afa, atha, asa RESULTS Main effect: F(2, 22) = 25,926, p<,01** No difference between /Ɵ/ and /s/: p>,05 University of Silesia

L2 onset ifi, ithi, isi RESULTS No main effect: F(2, 22) = 3,097, p>,05 University of Silesia

L2 onset ufu, uthu, usu RESULTS Main effect: F(2, 22) = 32,421, p<,01** Significant difference between /f/ and /Ɵ/: p<,01** No difference between /Ɵ/ and /s/: p>,05 University of Silesia

L2 transitions afa, atha, asa RESULTS L2 transitions afa, atha, asa Main effect: F(2, 22) = 12,951, p<,01** Significant difference between /f/ and /Ɵ/: p<,01** No difference between /Ɵ/ and /s/: p>,05 University of Silesia

L2 transitions ifi, ithi, isi RESULTS L2 transitions ifi, ithi, isi Main effect: F(2, 22) = 5,216, p<,05* Significant difference between /f/ and /Ɵ/: p<,05* No difference between /Ɵ/ and /s/: p>,05 University of Silesia

L2 transitions ufu, uthu, usu RESULTS L2 transitions ufu, uthu, usu Main effect: F(2, 22) = 12,557, p<,01** Significant difference between /f/ and /Ɵ/: p<,05* No difference between /Ɵ/ and /s/: p>,05 University of Silesia

Centre of gravity RESULTS Main consonant effect: F(2, 22) = 104,67, p<,01** No significant difference between /f/ and /Ɵ/: p>,05 Significant difference between /Ɵ/ and /s/: p<,01** Significant consonant x vowel interaction: F(4, 44) = 9,439, p<,01** University of Silesia

Root mean square amplitude in Pa RESULTS Root mean square amplitude in Pa Main consonant effect: F(2, 22) = 21,564, p<,01** No significant difference between /f/ and /Ɵ/: p>,05 Significant difference between /Ɵ/ and /s/: p<,01** No significant consonant x vowel interaction: F(4, 44) = 1,57, p>05 University of Silesia

CONCLUSIONS Spectral peak not a reliable cue University of Silesia

Overall noise intensity CONCLUSIONS Overall noise intensity distinguishes /Ɵ/ from /s/, does not distinguish /Ɵ/ from /f/ University of Silesia

distinguishes /Ɵ/ from /f/ for /i/ and /u/ CONCLUSIONS L2 onset distinguishes /Ɵ/ from /f/ for /i/ and /u/ does not distinguish /Ɵ/ from /s/ University of Silesia

distinguishes /Ɵ/ from /f/ for /i/, /a/ and /u/ CONCLUSIONS L2 transitions distinguishes /Ɵ/ from /f/ for /i/, /a/ and /u/ does not distinguish /Ɵ/ from /s/ University of Silesia

distinguishes /Ɵ/ from /s/, does not distinguish /Ɵ/ from /f/ CONCLUSIONS Centre of gravity distinguishes /Ɵ/ from /s/, does not distinguish /Ɵ/ from /f/ University of Silesia

distinguishes /Ɵ/ from /s/, does not distinguish /Ɵ/ from /f/ CONCLUSIONS RMS amplitude distinguishes /Ɵ/ from /s/, does not distinguish /Ɵ/ from /f/ University of Silesia

Analysing interdental fricatives in the learners’ phonological system: CONCLUSIONS Analysing interdental fricatives in the learners’ phonological system: /Ɵ/ vs. /s/ - overall noise intensity - centre of gravity - root mean square amplitude /Ɵ/ vs. /f/ - L2 onset - L2 transitions University of Silesia