Dialect Simulation through Prosody Transfer: A preliminary study on simulating Masan dialect with Seoul dialect Kyuchul Yoon Division of English, Kyungnam University The Autumn Conference of The Association of Modern British & American Language & Literature University of Ulsan,

2 Table of Contents Background & motivation Goal of the current work Prosody transfer (PSOLA algorithm) Preparation of stimuli Listening test & evaluation Future work

3 Background & motivation Differences among dialects –Segmental differences Fricative differences in the time domain (Lee, 2002) –Busan fricatives have shorter frication/aspiration intervals than for Seoul Fricative differences in the frequency domain (Kim et al., 2002) –The low cutoff frequency of Kyungsang fricatives was higher than for Cholla fricatives (> 1,000 Hz) –Non-segmental or prosodic differences Intonation or fundamental frequency (F0) contour difference Intensity contour difference Segment durational difference Voice quality difference

4 Background & motivation Concatenative text-to-speech (TTS) synthesizers –Concatenation-based –Concatenation units: e.g. diphones –Concatenation units from pre-recorded utterances of a particular dialect –No need for modeling segmental properties (cf. formant-based synthesizers) Strength/Weakness –Usually single dialect

5 Background & motivation To build a multi-dialectal TTS synthesizer –Concatenation units: Multiple dialects –User-selectable dialects Question: –Scenario A: A multi-dialectal TTS system containing multiple concatenation units from all the dialects involved –Scenario B: Use the concatenation units from a single dialect and simulate the other dialects

6 Background & motivation The answer has implications on the cost and the complexity of building multi-dialect TTS systems. Scenario B –Simpler & cheaper –Need for simulating the segmental/non-segmental aspects of the other dialects involved. –Scenario A may be the ultimate solution Concatenative TTS systems –Since modeling the segmental aspects of the concatenation units in the frequency domain can be difficult, the non-segmental or prosodic aspects should be manipulated.

7 Background & motivation The imaginary TTS system (Scenario B) Concatenation units from dialect 1 Dialect 2Dialect 3Dialect 4 Simulate prosodic aspects

8 Background & motivation The questions are; Would the simulated dialects be good enough? In other words, Would the segmental effects be negligible in perceiving the simulated dialects as authentic?

9 Goal of the current work The goal is to test the viability of this scenario with an imaginary system: –Simulate Masan dialect with Seoul dialect The simulated Masan dialect will have –the speech segments of Seoul dialect –the prosody of Masan dialect (F0, intensity, duration) –the voice source of Masan dialect (not tested)

10 Goal of the current work The imaginary system would have –the concatenation units from Seoul dialect and –the ‘near-perfect’ prosody-generating module and –have to simulate the other dialects, e.g. Masan dialect The imaginary TTS system will be implemented with –the recorded utterances of Seoul dialect –the Masan prosody (F0, intensity, duration) from recorded Masan utterances –the voice source of recorded Masan utterances (not tested)

11 Prosody transfer (PSOLA algorithm) Three aspects of the prosody –Fundamental frequency (F0) contour –Intensity contour –Segmental durations Pitch-Synchronous OverLap and Add (PSOLA) algorithm (Mouline & Charpentier, 1990) –Implemented in Praat (Boersma, 2005) –Use of a script for semi-automatic segment-by-segment manipulation (Yoon, 2006)

12 Prosody transfer (PSOLA algorithm) PSOLA algorithm –Windowing pitch periods of the original signal –Rearranging windowed pitch periods to Stretch/shrink the signal (involves adding/deleting windowed pitch periods) Change, i.e. increase/decrease the F0 of the signal (involves adding/deleting windowed pitch periods)

13 Prosody transfer (PSOLA algorithm) original waveform windowed waveform shortened waveform waveform with lower F0

14 Prosody transfer (PSOLA algorithm) Prosody transfer using the PSOLA algorithm –Align segments btw/ Masan and Seoul utterances –Make the segment durations of the two identical –Make the two F0 contours identical –Make the two intensity contours identical

15 Prosody transfer (PSOLA algorithm) Align segments btw/ Masan and Seoul utterances Make the segment durations of the two utterances identical ㅂㅏㄹㅏㅁ “… 바람 …” Masan ㅏㅏ Seoul stretch shrink ㅂㄹㅁ

16 Prosody transfer (PSOLA algorithm) ㅂㅏㄹㅏㅁ Masan Seoul ㅂㅏㄹㅏㅁ Masan F0 Seoul F0 Make the two F0 contours identical

17 Prosody transfer (PSOLA algorithm) Seoul intensity ㅂㅏㄹㅏㅁ Masan Seoul ㅂㅏㄹㅏㅁ Masan intensity Make the two intensity contours identical

18 Preparation of test stimuli

19 Preparation of control stimuli

20 Preparation of experiment stimuli 바다에 보물섬이 없다 교수님 가시는 길이 구미로 … 동대구에 볼 일이 없습니다 쌀 사고 난 후에 와라 바람이 불어서 먼지가 많다 싸기는 해 보여도, 비싸기는 … 서울에 사는 삼촌이 왔다 Masan dialect prosody-donor (A) prosody-recipient (B) Seoul dialect prosody-recipient (C) prosody-recipient (D) 7 test stimuli (used) test stimuli (not used) 7 control stimuli (used)

21 Listening test & evaluation 14 test/control stimuli normalized & randomized Presented to 4 Masan listeners for magnitude estimation –On a scale of 1 (bad) to 10 (best) –Qualitatively assessed –Used Praat experimentMFC object –Repetition of each stimulus : up to 10 times (User can press “replay” button)

22 Listening test & evaluation

23 Listening test & evaluation

24 Future work Carefully control the phonological, morphological, and syntactic aspects of the test sentences Try the voice source (as opposed to the filter) of Masan utterances

25 Future work Compare spectra btw/ Masan and Seoul /i/ –window length 50 msec. 바람이 H1 & H2

26 Original Masan dialect Original Seoul dialect Simulated Masan dialect: Seoul segments + Masan prosody Simulated Masan dialect: Seoul segments + Masan prosody + Masan voice source

27 Appendix 바다에 보물섬이 없다 교수님 가시는 길이 구미로 … 동대구에 볼 일이 없습니다 쌀 사고 난 후에 와라 바람이 불어서 먼지가 많다 싸기는 해 보여도, 비싸기는 … 서울에 사는 삼촌이 왔다 Seoul dialect prosody-donor (A) prosody-recipient (B) Masan dialect prosody-recipient (C) prosody-recipient (D) test stimuli control stimuli

28 References [1] Kyung-Hee Lee, “Comparison of acoustic characteristics between Seoul and Busan dialect on fricatives”, Speech Sciences, Vol.9/3, pp , [2] Hyun-Gi Kim, Eun-Young Lee, and Ki-Hwan Hong, “Experimental phonetic study of Kyungsang and Cholla dialect using power spectrum and laryngeal fiberscope”, Speech Sciences, Vol.9/2, pp.25-47, [3] Kyuchul Yoon, “Swapping native and non-native speakers' prosody using PSOLA algorithm”, Proceedings of the Korean Society of Phonetic Sciences and Speech Technology, Spring Conference, pp.77-81, [4] E. Moulines and F. Charpentier, “Pitch synchronouswaveform processing techniques for text-to-speech synthesis using diphones”, Speech Communication, 9:n 5-6, [5] P. Boersma, “Praat, a system for doing phonetics by computer”, Glot International, Vol.5, 9/10, pp , 2005.