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

2. 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

3. 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

4. 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

5. 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

6. 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

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

8. 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

9. 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

10. 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

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

12. 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

13. 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

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

15. 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

16. 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

17. 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

18. 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

19. 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

20. 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

21. CONCLUSIONS
Spectral peak
not a reliable cue
University of Silesia

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

23. 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

24. 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

25. 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

26. 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

27. 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