• Smart Media Journal
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• v.12 no.2
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• pp.56-65
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• 2023

In broadcasts such as news and coverage programs, voice is modulated to protect the identity of the informant. Adjusting the pitch is commonly used voice modulation method, which allows easy voice restoration to the original voice by adjusting the pitch. Therefore, since broadcast voice modulation methods cannot properly protect the identity of the speaker and are vulnerable to security, a new voice modulation method is needed to replace them. In this paper, using the Lightweight speech de-identification model as the evaluation target model, we compare speech de-identification performance with broadcast voice modulation method using pitch modulation. Among the six modulation methods in the Lightweight speech de-identification model, we experimented on the de-identification performance of Korean speech as a human test and EER(Equal Error Rate) test compared with broadcast voice modulation using three modulation methods: McAdams, Resampling, and Vocal Tract Length Normalization(VTLN). Experimental results show VTLN modulation methods performed higher de-identification performance in both human tests and EER tests. As a result, the modulation methods of the Lightweight model for Korean speech has sufficient de-identification performance and will be able to replace the security-weak broadcast voice modulation.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.337-342
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• 1996

In prevoius works we have repored phonetic similarities between Japanese and Spanish voweis and syiiabic sounds. (1) (2) (3) (4). In the present communication we explore the relative importance of duration of the consonantal segment to elicit Spanish /l/ - /r/ distinction by native j Japanese talkers. Three Argentine and three trained native Japanese talkers recorded /l-r/ combined with /a/ in VCV sequences. Modifications of consonant duration and vowel context with transitions were m made by editing natural /ala/ sounds. Mixed VCV were produced by combining sounds of both languages. Perceptual tests were produced by combining sounds of both languages perceptual performed presenting the speech material, to native t trained and non trained Japanese listeners. In a tirst sessIOn a d discrimination procedure was applied. The items were arranged in pairs a and listeners Nere told to indicate the pair that sounded different. In the f following session they were asked to identify and type the letter corresponding to each one of the items. Responses arc examined in tenns of critical duration of the interval between vowels. Preliminary results indicate that the duration of intervocalic intervais was a relevant cue for the identification of /l/ and /r/. It seems that to differentiate the two sounds, Japanese listeners required relatively longer interval steps than the argentine suhjects. There was a tendency to conhlse more frequently /l/ for /r/ than viceversa.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.521-528
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• 1996

This presentation explores on the perceptual characteristics of the lateral sound /l/ in CV syllables. At initial position we found that /l/ has well marked formant transitions. Then several questions arise: 1) are these formant structures dependent on the following vowel\ulcorner. 2) Are the formant transitions giving an additional cue for the identification\ulcorner Considering that the French vocalic system presents a greater variety of vowels than Spanish, several experiments were designed to verify to what extent a more extensive range of vocalic timbres contribute to the perception of /l/. Natural emissions of /l/ produced in Argentine Spanish and Canadian French CV syllables were recorded, where V was successively /i, e, a, o, u/ for Spanish and /i, e, $\varepsilon$, a, $\alpha$, o, u, y, \phi$/ for French. For each item, the segment C was maintained and V was replaced by cutting & splicing by each of the remaining vowels without transitions. Results of the identification tests for Spanish show that natural /l/ segments with low Fl and high formants F3, F4 can be clearly identified in the /i, e, u/ vowel contexts without transitions. For French subjects the combination of /l/ with a vowel without transitions reflected correct identifications for its own original vowel context in /e, $\varepsilon$, y, $\phi$/. For both languages, in all these combinations, F1 values remained rather steady along the syllable. In the case of /o, u/ very likely the F2 difference lead to a variety of perceptions of the original /l/. For example in Ilul, French subjects reported some identifications of /l/ as a vowel, mainly /y/. Our observations reinforce the importance of F1 as a relevant cue for /l/, and the incidence of the relative distance between formants frequencies of both components.