Vol.2015-SLP-105 No.3
2015/2/27

৘ใॲཧֶձ‫ڀݚ‬ใࠂ
IPSJ SIG Technical Reportӆ཯ɾԻӆͷ෦෼ิਖ਼ʹ‫ͮ͘ج‬࿩ऀੑΛอ࣋ͨ͠೔ຊਓӳ‫ޠ‬Ի੠߹੒ͱӳ‫ޠ‬शख़౓͕༩͑ΔӨ‫ڹ‬େౡ ༔࢘1ߴಓ ৻೭հ1‫ ాށ‬ஐ‫ج‬1

Sakriani Sakti1

Graham Neubig1

தଜ ఩1֓ཁɿ੠࣭ม‫׵‬΍ HMM Ի੠߹੒Λ༻͍ͨ೔ӳؒΫϩεϦϯΨϧԻ੠߹੒͸ɼಉ‫ؒޠݴ‬ͷ৔߹ͱൺֱ͠
ͯɼ࿩ऀੑͷ௿͍Ի੠Λ߹੒͢Δ܏޲ʹ͋Δɽ͜Εʹର͠զʑ͸ɼ೔ຊਓӳ‫ޠ‬ʢERJ: English Read by

Japaneseʣͷར༻ɼ·ͨɼ೔ຊਓӳ‫ޠ‬ͷӆ཯‫ޡ‬Γʹର͢Δӆ཯ิਖ਼๏ʹΑΓɼ࿩ऀੑΛ‫͘ڧ‬൓өͭͭࣗ͠વ
ੑΛվળ͢Δख๏ΛఏҊ͍ͯ͠Δɽ͔͠͠ͳ͕ΒɼධՁऀͷ฼‫ൃͱޠ‬࿩ऀͷӳ‫ޠ‬शख़౓ʹର͢Δิਖ਼๏ͷӨ‫ڹ‬ͷҧ͍͸े෼ʹௐࠪ͞Ε͓ͯΒͣɼ·ͨɼ೔ຊਓӳ‫ޠ‬ͷࣗવੑ௿ԼͷཁҼͰ͋ΔԻӆ‫ޡ‬Γʹ͍ͭͯ΋ߟྀ͞Ε͍ͯͳ͍ɽຊߘͰ͸ɼධՁऀͷ฼‫ൃͱޠ‬࿩ऀͷӳ‫ޠ‬शख़౓͕ӆ཯ิਖ਼ͷޮՌʹ༩͑ΔӨ‫ڹ‬Λௐࠪ͢Δͱͱ΋ʹɼ৽ͨʹແ੠ࢠԻεϖΫτϧஔ‫ͮ͘جʹ׵‬Իӆิਖ਼๏ΛఏҊ͢Δɽ࣮‫ݧ‬తධՁʹΑΓɼʢ̍ʣύϫʔิਖ਼ʹΑΔࣗવੑͷվળޮՌ͸ɼӳ‫ޠ‬฼‫ޠ‬࿩ऀʹΑΔධՁʹ͓͍ͯ‫ݦ‬ஶʹ‫ݟ‬ΒΕΔ͜ͱɼʢ̎ʣӳ‫ޠ‬शख़౓ʹؔΘΒͣɼӆ཯ิਖ਼๏ʹΑΓࣗવੑ͕վળ͢Δ͜ͱɼ
ʢ̏ʣԻӆิਖ਼๏΋ࣗવੑվળʹ༗ޮͰ͋Δ
͜ͱΛࣔ͢ɽ
Ωʔϫʔυɿ೔ຊਓӳ‫ޠ‬, HMM Ի੠߹੒, ӆ཯ิਖ਼, Իӆิਖ਼, ࿩ऀੑEnglish-Read-By-Japanese Speech Synthesis Preserving Speaker
Individuality Based on Partial Correction of Prosody and Phonetic
Sounds and Eﬀects of English Proﬁciency Level on Its Performance
Yuji Oshima1

Shinnosuke Takamichi1 Tomoki Toda1
Satoshi Nakamura1

Sakriani Sakti1

Graham Neubig1

Abstract: Cross-lingual speech synthesis for generating naturally sounding English speech uttered by
Japanese speakers based on voice conversion and HMM-based speech synthesis tends to cause the degradation of speaker individuality in synthetic speech compared to intra-lingual speech synthesis. To address
this issue, we have proposed an ERJ(English Read by Japanese) speech synthesis method to preserve speakerindividuality in synthetic speech and a prosody correction method to improve its naturalness. However, theireﬀectiveness has never been evaluated by native listeners: the eﬀects of each speaker’s English proﬁciency
level on their performance have never been evaluated; and incorrect phonetic sounds of ERJ have never beenaddressed. In this paper, we evaluate these points by applying the proposed method to multiple speakers withvarious English proﬁciency levels and also propose a correction method of some incorrect phonetic sounds
based on spectrum swapping for unvoiced consonants. The experimental results demonstrate that (1) theeﬀectiveness of power correction is well conﬁrmed by native listeners; (2) the naturalness of ERJ synthetic
speech is successfully improved over various English prociency levels by the prosody correction method; and(3) the proposed phonetic sound correction method is also eﬀective for further improving its naturalness.
Keywords: English-Read-by-Japanese (ERJ), HMM-based speech synthesis, prosodical correction, phonetic
correction, speaker individualityⓒ 2015 Information Processing Society of Japan1

Vol.2015-SLP-105 No.3
2015/2/27

৘ใॲཧֶձ‫ڀݚ‬ใࠂ
IPSJ SIG Technical ReportƵƌĂƚŝŽŶ
ŵŽĚĞů

1. ͸͡Ίʹ
ΫϩεϦϯΨϧԻ੠߹੒͸ɼ͋Δ‫ޠݴ‬ͷൃ࿩ऀͷ࿩ऀੑ,DDΛҟ‫ޠݴ‬ͷ߹੒Ի੠ʹ൓өͤ͞Δٕज़Ͱ͋Γɼ࿩ऀੑʹΑ^ƉĞĐƚƌĂů
ŵŽĚĞůΔ৘ใ‫ݯ‬ͷಛఆΛଅ͠ɼԁ‫ͳ׈‬ίϛϡχέʔγϣϯΛଅਐ
͢Δ໾ׂΛ୲͏ɽಛʹ೔ຊͰ͸ɼ೔ӳؒʹ͓͚Δ߹੒ٕज़ͷधཁ͕ߴ͘ɼԻ੠຋༁γεςϜɼւ֎өըͷਧ͖ସ͑΍䠆ĚĂƉƚĂƚŝŽŶ

䠖ĚĂƉƚĂƚŝŽŶĚĂƚĂĚĂƉƚďǇƋ͘;ϮͿΘ;ϯͿ^ŽƵƌĐĞƐƉĞĂŬĞƌ͛ƐŵŽĚĞů

ǆĐŝƚĂƚŝŽŶŵŽĚĞů䠆䠆 䠆 䠆 䠆dĂƌŐĞƚ
^ƉĞĂŬĞƌ͛ƐŵŽĚĞů

ਤ 1 HMM Ի੠߹੒ʹ͓͚ΔϞσϧదԠ

CALL γεςϜ [1] ΁ͷԠ༻͕‫ظ‬଴͞ΕΔɽ͜Ε·Ͱʹɼ౷‫ܭ‬త੠࣭ม‫ٕ׵‬ज़ [2] ΍ӅΕϚϧίϑϞσ

Fig. 1 Model adaptation in HMM-based speech synthesis.

ϧ ʢHMM: Hidden Markov Modelʣʹ‫ͮ͘ج‬Ի੠߹੒ [3]͋Δ࿩ऀͷ HMM ͔Β໨ඪ࿩ऀͷ HMM ΛߏஙͰ͖Δɽ༧ʹ͓͚Δ࿩ऀదԠٕज़ [4] ʹ͓͍ͯɼӳ‫ޠ‬Λ฼‫͢ͱޠ‬Δ࿩

Ίֶश͓͍ͯͨ͠దԠ‫ݩ‬Ϟσϧͱ໨ඪ࿩ऀͷదԠσʔλΛऀͷԻ੠ʹରͯ͠ɼόΠϦϯΨϧԻ੠΍೔ຊ‫ޠ‬Ի੠ͱ͍ͬ

༻͍ͯɼదԠ‫ݩ‬ϞσϧͷύϥϝʔλΛม‫͢ܗ‬Δ͜ͱͰɼ໨

ͨࣗવੑͷߴ͍Ի੠σʔλΛ‫ͨ͠༻׆‬࿩ऀม‫ॲ׵‬ཧΛࢪ͢ඪ࿩ऀ΁ͱదԠ͞ΕͨϞσϧ͕ಘΒΕΔɽదԠ‫ޙ‬ͷฏ‫ۉ‬ϕख๏ [5], [6], [7] ͕޿͘‫͞ڀݚ‬Ε͍ͯΔɽ͜ΕΒͷख๏͸ɼΫτϧ μ̂c ͱ‫ڞ‬෼ࢄߦྻ Σ̂c ͸࣍ࣜͰ‫͞ࢉܭ‬ΕΔɽ

ൺֱతߴ͍ࣗવੑΛ࣋ͭӳ‫ޠ‬Ի੠Λ߹੒Ͱ͖ΔҰํͰɼಉҰ‫͚͓ʹؒޠݴ‬Δ߹੒Ի੠ͱൺֱ͢Δͱɼ࿩ऀੑͷྼԽΛট͘܏޲͕͋Δ [5]ɽμ̂c = Aμc + b(2)Σ̂c = AΣc AT(3)͜Εʹର͠զʑ͸ɼ೔ຊਓӳ‫ޠ‬ʢERJ: English Read by͜͜ͰɼదԠߦྻ A ͱόΠΞεϕΫτϧ b ͸ճ‫ؼ‬ύϥϝʔ

Japaneseʣ[8] Λར༻ͨ͠Ϟσϧߏஙɼ·ͨɼ೔ຊਓӳ‫ޠ‬ͷλͰ͋Γɼෳ਺ͷ෼෍͕ଐ͢Δճ‫ؼ‬Ϋϥε͝ͱʹਪఆ͞Εӆ཯‫ޡ‬Γʹର͢Δӆ཯ิਖ਼๏ʹΑΓɼ࿩ऀੑΛ‫͘ڧ‬൓ө͠ΔɽHMM Ի੠߹੒Ͱ͸ɼεϖΫτϧύϥϝʔλɼԻ‫ݯ‬ύͭͭࣗવੑΛվળ͢Δख๏ΛఏҊ͍ͯ͠Δ [9]ɽ͔͠͠ͳ

ϥϝʔλɼঢ়ଶ‫ܧ‬ଓ௕͕ਖ਼‫ن‬෼෍ͰϞσϧԽ͞Ε͓ͯΓɼ͕ΒɼຊఏҊ๏ͷධՁ৚݅͸ɼ೔ຊ‫ޠ‬฼‫ޠ‬࿩ऀ͔Β੒ΔධͦΕΒશͯʹରͯ͠దԠॲཧ͕ߦΘΕΔɽ͜ΕʹΑΓɼ෼Ձऀͱগ਺ൃ࿩ऀͷΈʹཹ·͓ͬͯΓɼධՁऀͷ฼‫ൃͱޠ‬અతಛ௃ͷΈͰͳ͘ӆ཯తಛ௃΋ಉ࣌ʹదԠՄೳʹͳΔɽ࿩ऀͷӳ‫ޠ‬शख़౓ʹΑΔӨ‫͕ڹ‬ௐࠪ͞Ε͍ͯͳ͍ɽ·ͨɼύϥϝʔλੜ੒࣌ʹ͸ɼೖྗςΩετΛղੳ͢Δ͜ͱͰ೔ຊਓӳ‫ޠ‬ͷࣗવੑ௿ԼͷཁҼͰ͋ΔԻӆ‫ޡ‬Γ͕ߟྀ͞ΕಘΒΕΔίϯςΩετʹ‫͖ͮج‬ɼจ HMM Λߏங͢Δɽͦ

͍ͯͳ͍ͨΊɼಘΒΕΔࣗવੑվળޮՌ͸‫ݶ‬ఆ͞ΕΔɽͷ‫ޙ‬ɼ‫ܧ‬ଓ௕Ϟσϧͷ໬౓࠷େԽʹΑΓঢ়ଶ‫ܧ‬ଓ௕ΛܾຊߘͰ͸ɼධՁऀͷ฼‫ൃͱޠ‬࿩ऀͷӳ‫ޠ‬शख़౓͕ӆ཯ิఆͨ͠ͷͪɼ੩తɾಈతಛ௃ྔؒͷ໌ࣔతͳ੍໿ͷԼͰɼਖ਼ͷޮՌʹ༩͑ΔӨ‫ڹ‬Λௐࠪ͢Δͱͱ΋ʹɼແ੠ࢠԻεϖ

HMM ͷ໬౓࠷େԽʹΑΓύϥϝʔλΛੜ੒ [11] ͠ɼϘΫτϧஔ‫ͮ͘جʹ׵‬Իӆิਖ਼๏ΛఏҊ͢Δɽ࣮‫ݧ‬తධՁʹίʔμʹ‫ͮ͘ج‬೾‫ܗ‬ੜ੒ॲཧΛ‫ͯܦ‬Ի੠͕߹੒͞ΕΔɽΑΓɼʢ̍ʣύϫʔิਖ਼ʹΑΔࣗવੑͷվળޮՌ͸ɼӳ‫ޠ‬฼౓ʹؔΘΒͣɼӆ཯ิਖ਼๏ʹΑΓࣗવੑ͕վળ͢Δ͜ͱɼ

3. ೔ຊਓӳ‫ޠ‬Ի੠߹੒ʹ͓͚Δӆ཯ิਖ਼๏ͱ
Իӆิਖ਼๏ʢ̏ʣԻӆิਖ਼๏΋ࣗવੑվળʹ༗ޮͰ͋Δ͜ͱΛࣔ͢ɽ

3.1 ϞσϧదԠʹΑΔӆ཯ิਖ਼๏‫ޠ‬࿩ऀʹΑΔධՁʹ͓͍ͯ‫ݦ‬ஶͰ͋Δ͜ͱɼʢ̎ʣӳ‫ޠ‬शख़

ਤ 2 ʹϞσϧదԠʹΑΔӆ཯ิਖ਼๏ͷ֓ཁΛࣔ͢ɽ·

2. HMM Ի੠߹੒ʹ͓͚ΔదԠٕज़ͣɼӳ‫ޠ‬฼‫ޠ‬࿩ऀͷӳ‫ޠ‬Ի੠Λ༻͍ͯɼӳ‫ޠ‬฼‫ޠ‬࿩ऀʹର

ਤ 1 ʹ HMM Ի੠߹੒ʹ͓͚ΔϞσϧదԠͷ֓ཁਤΛ

͢Δ࿩ऀґଘ HMM Λֶश͢Δɽ‫؍‬ଌσʔλͱͯ͠༻͍Δ

ࣔ͢ɽHMM Ի੠߹੒Ͱ͸ɼԻ੠ͷεϖΫτϧύϥϝʔλɼԻ੠ύϥϝʔλ͸ɼର਺ύϫʔɼεϖΫτϧแབྷύϥϝʔԻ‫ݯ‬ύϥϝʔλɼঢ়ଶ‫ܧ‬ଓ௕ΛɼHMM ʹ‫ͮ͘ج‬౷Ұతͳ࿮λɼԻ‫ݯ‬ύϥϝʔλͰ͋Γɼ֤ύϥϝʔλʹର͢Δग़ྗ֬૊ΈͰϞσϧԽ͢Δ [10]ɽίϯςΩετΫϥελϦϯάʹ

཰෼෍ͱঢ়ଶ‫ܧ‬ଓ௕෼෍͕ಘΒΕΔɽ࣍ʹɼ໨ඪ೔ຊ‫ޠ‬฼ΑΔΫϥε c ͷग़ྗ֬཰෼෍ bc (ot ) ͸ɼ࣍ࣜͰද͞ΕΔɽ

bc (ot ) = N (ot ; μc , Σc )(1)‫ޠ‬࿩ऀͷ࿩ऀੑΛ൓өͨ͠ӳ‫ޠ‬Ի੠߹੒༻ HMM Λߏங͢ΔͨΊʹɼ໨ඪ࿩ऀͷ೔ຊਓӳ‫ޠ‬Ի੠Λ༻͍ͯɼ ӳ‫ޠ‬฼‫ޠ‬࿩ऀͷ HMM ΛదԠ͢Δɽຊख๏Ͱ͸ɼ೔ຊਓӳ‫ޠ‬Ի੠ͷ




 
ͨͩ͠ɼot = c͸ɼ࣌ࠁ t ʹ͓͚Δ੩త
t , Δct , ΔΔctࣗવੑΛྼԽͤ͞ΔཁҼͱͯ͠ɼ‫ܧ‬ଓ௕‫ͼٴ‬ύϫʔʹண໨ಛ௃ྔ ct ͱͦͷҰ࣍ͱೋ࣍ͷಈతಛ௃ྔ Δct ɼΔΔct ͷ݁͠ɼঢ়ଶ‫ܧ‬ଓ௕ͱର਺ύϫʔҎ֎ʹର͢ΔϞσϧύϥϝʔ߹ϕΫτϧΛද͠ɼN (·; μc , Σc ) ͸ɼฏ‫ ۉ‬μc ɼ‫ڞ‬෼ࢄߦྻλͷΈΛదԠ͢Δ͜ͱͰɼӳ‫ޠ‬฼‫ޠ‬࿩ऀͷӆ཯Λߟྀͨ͠Σc Λ࣋ͭਖ਼‫ن‬෼෍Λද͢ɽ೔ຊਓӳ‫ޠ‬ͷ HMM Λߏங͢ΔɽຊదԠ๏ʹΑΓɼ໨ඪ೔

1

HMM Ի੠߹੒Ͱ͸ɼϞσϧదԠٕज़Λ༻͍Δ͜ͱͰɼຊ‫ޠ‬฼‫ޠ‬࿩ऀͷ࿩ऀੑΛग़དྷΔ‫ݶ‬Γอ࣋ͨ͠··ɼࣗવੑಸྑઌ୺Պֶٕज़େֶӃେֶɹ৘ใՊֶ‫ڀݚ‬Պ͕վળ͞Εͨ೔ຊਓӳ‫ޠ‬Ի੠ͷ߹੒͕ՄೳʹͳΔ [9]ɽⓒ 2015 Information Processing Society of Japan2

Vol.2015-SLP-105 No.3
2015/2/27

৘ใॲཧֶձ‫ڀݚ‬ใࠂ
IPSJ SIG Technical Reportද 1ධՁʹ༻͍Δख๏

Table 1 Synthetic speech samples used for evaluation.
ख๏໊

ֶशσʔλ

దԠσʔλ

ӆ཯ิਖ਼

Իӆิਖ਼

ERJ

೔ຊਓӳ‫ޠ‬

–

ͳ͠

ͳ͠

2

HMM+VCӳ‫ޠ‬฼‫ޠ‬࿩ऀӳ‫ޠ‬

–

–

–

Adapt

ӳ‫ޠ‬฼‫ޠ‬࿩ऀӳ‫ޠ‬೔ຊਓӳ‫ޠ‬

ͳ͠

ͳ͠

Dur.

ӳ‫ޠ‬฼‫ޠ‬࿩ऀӳ‫ޠ‬೔ຊਓӳ‫ޠ‬ঢ়ଶ‫ܧ‬ଓ௕

ͳ͠

Dur.+Pow.

ӳ‫ޠ‬฼‫ޠ‬࿩ऀӳ‫ޠ‬೔ຊਓӳ‫ޠ‬ঢ়ଶ‫ܧ‬ଓ௕ɼର਺ύϫʔͳ͠

Dur.+Pow.+UVCӳ‫ޠ‬฼‫ޠ‬࿩ऀӳ‫ޠ‬೔ຊਓӳ‫ޠ‬ঢ়ଶ‫ܧ‬ଓ௕ɼର਺ύϫʔແ੠ࢠԻεϖΫτϧ

Nativeӳ‫ޠ‬฼‫ޠ‬࿩ऀӳ‫ޠ‬

–

–

–

3.2 ແ੠ࢠԻεϖΫτϧஔ‫ʹ׵‬ΑΔԻӆิਖ਼Z:ƐƉĞĞĐŚ

ਤ 3 ʹແ੠ࢠԻεϖΫτϧஔ‫ͮ͘جʹ׵‬Իӆิਖ਼๏ͷखॱΛࣔ͢ɽఏҊ๏Ͱ͸ɼӳ‫ޠ‬฼‫ޠ‬࿩ऀͷεϖΫτϧύϥ
ϝʔλΛ෦෼తʹ࢖༻͢Δ͜ͱͰɼ೔ຊਓӳ‫ޠ‬ͷԻӆΛิEĂƚŝǀĞŶŐůŝƐŚ
ƐƉĞĞĐŚ

ਖ਼͢ΔɽԻߴ΍฼Ի͸࿩ऀੑ஌֮ʹ‫͘ڧ‬Ө‫͢ڹ‬Δ [12] ҰํͰɼແ੠ࢠԻͷ࿩ऀґଘੑ͸খ͍͞ͱ༧૝͞ΕΔɽͦͷͨΊɼ೔ຊਓӳ‫ޠ‬ͷແ੠ࢠԻͷஔ‫ʹ׵‬ΑΓɼ࿩ऀੑΛอ࣋ͭͭࣗ͠વੑΛվળͰ͖Δͱߟ͑ΒΕΔɽ
·ͣɼӳ‫ޠ‬฼‫ޠ‬࿩ऀ HMM ͱӆ཯ิਖ਼͞Εͨ೔ຊਓӳ‫ޠ‬

HMM ͔ΒɼͦΕͧΕԻ੠ύϥϝʔλΛੜ੒͢Δɽ͜͜Ͱɼ
֤ HMM ͸ಉҰͷ‫ܧ‬ଓ௕ϞσϧΛ༗͢ΔͨΊɼੜ੒ύϥແ੠ࢠԻʹରԠ͢ΔϑϨʔϜͷΈΛɼӳ‫ޠ‬฼‫ޠ‬࿩ऀͷεϖǆĐŝƚĂƚŝŽŶ

ĚĂƉƚ^ƉĞĐƚƌƵŵ
ǆĐŝƚĂƚŝŽŶ

WŽǁĞƌ

WŽǁĞƌ

ƵƌĂƚŝŽŶ

ƵƌĂƚŝŽŶ

Z:,^DDƐǁŝƚŚŵŽĚŝĨŝĞĚ
ƉƌŽƐŽĚǇ

ਤ 2 ϞσϧదԠʹΑΔӆ཯ิਖ਼ͷ֓ཁ

Fig. 2 An overview of the prosody correction method based onmodel adaptation technique.
EĂƚŝǀĞ,^DDƐϝʔλ͸࣌ؒతʹରԠ෇͚ΒΕ͍ͯΔ͜ͱʹ஫ҙ͢Δɽ࣍
ʹɼ೔ຊ‫ޠ‬฼‫ޠ‬࿩ऀͷεϖΫτϧύϥϝʔλ‫ྻܥ‬ͷ͏ͪɼ^ƉĞĐƚƌƵŵ
EĂƚŝǀĞ,^DDƐZ:,^DDƐǁŝƚŚŵŽĚŝĨŝĞĚ
ƉƌŽƐŽĚǇ

^ƉĞĐƚƌĂůƉĂƌĂŵĞƚĞƌ
^ǁĂƉƵŶǀŽŝĐĞĚĐŽŶƐŽŶĂŶƚ
ǁŝƚŚEĂƚŝǀĞ͛Ɛ^ǇŶƚŚĞƐŝƐ

WŚŽŶĞŵĞŵŽĚŝĨŝĞĚƐǇŶƚŚĞƚŝĐƐƉĞĞĐŚŽĨZ:ƐƉĞĂŬĞƌ

^ƉĞĐƚƌĂůƉĂƌĂŵĞƚĞƌ
ǆĐŝƚĂƚŝŽŶƉĂƌĂŵĞƚĞƌ

Ϋτϧύϥϝʔλʹஔ‫͢׵‬Δɽஔ‫׵‬ͷࡍʹɼஔ‫ޙ׵‬ͷεϖΫτϧͱ‫ݩ‬ͷ༗੠ʗແ੠৘ใͷෆҰகʹΑΓੜ͡ΔԻ࣭ྼԽΛճආ͢ΔͨΊɼແ੠ࢠԻͷϑϨʔϜʹ͓͚Δӳ‫ޠ‬฼‫ޠ‬࿩ऀͷ F0 ͕༗੠Ͱ͋Δ৔߹ɼ౰֘ϑϨʔϜΛஔ‫͍ͳ͠׵‬ɽਤ 3ແ੠ࢠԻεϖΫτϧஔ‫ʹ׵‬ΑΔԻӆิਖ਼ͷ֓ཁ

Fig. 3 An overview of the phoneme correction method basedon spectrum swapping of the unvoiced consonants.

τϦʔϜͰֶश͢ΔɽϞσϧదԠ͸ CSMAPLR+MAP[16]4. ࣮‫ݧ‬తධՁ
4.1 ࣮‫ݧ‬৚ֶ݅शσʔλͱͯ͠ɼCMU ARCTIC Ի੠σʔλϕʔε [13]Λར༻͠ɼճ‫ʹྻߦؼ‬͸੩తಛ௃ྔɼ1 ࣍ͱ 2 ࣍ͷಈతಛ௃ྔʹରԠͨ͠ϒϩοΫର֯ߦྻΛ༻͍Δɽͨͩ͠దԠ࣌
ʹ͸ɼదԠσʔλͷ࿩ऀͱಉ͡ੑผͷӳ‫ޠ‬฼‫ޠ‬࿩ऀͷσʔλͰֶश͞Εͨ HMM Λ༻͍Δɽதͷӳ‫ޠ‬฼‫ޠ‬࿩ऀͷஉঁ֤ 1 ໊ʹΑΔ A ηοτ 593 จΛఏҊ๏ʹΑΔӆ཯ิਖ਼ͷޮՌΛධՁ͢ΔͨΊʹɼද 1 ʹ

༻͍ΔɽධՁσʔλ͸ಉ B ηοτ 50 จͱ͢Δɽֶशσʔࣔ͢ख๏ʹΑΔ߹੒Ի੠Λ༻͍ͯɼ࿩ऀੑɼࣗવੑ‫໌ͼٴ‬λɼධՁσʔλɼ‫ͼٴ‬ɼదԠσʔλͷαϯϓϦϯάप೾਺͸ྎੑʹؔ͢Δओ‫؍‬ධՁΛ࣮ࢪ͢Δɽ

16 kHz Ͱ͋ΔɽԻ੠ύϥϝʔλͷ෼ੳʹ͸ STRAIGHT ෼ੳ [14] Λ࢖༻͠ɼεϖΫτϧಛ௃ྔͱͯ͠ɼର਺ύϫʔ͓Α

4.2 ϞσϧదԠʹΑΔӆ཯ิਖ਼ͷޮՌ

ͼ 1 ͔࣍Β 24 ࣍ͷϝϧέϓετϥϜ܎਺Λ༻͍ΔɽԻ‫ݯ‬

4.2.1 ӆ཯ิਖ਼๏ʹ͓͚ΔධՁऀͷ฼‫ޠ‬ͷӨ‫ڹ‬ಛ௃ྔͱͯ͠ɼର਺ F0 ‫ ͼٴ‬5 प೾਺ଳҬʹ͓͚Δฏ‫ۉ‬ඇप໨ඪ࿩ऀ͸ɼ20 ୅உੑͷ೔ຊ‫ޠ‬฼‫ޠ‬࿩ऀ 2 ໊ͱ͢Δɽ಺‫ظ‬੒෼Λ༻͍ΔɽϑϨʔϜγϑτ͸ 5 ms ͱ͢Δɽ͜ΕΒͷҰਓ͸ɼཹֶ‫ݧܦ‬ͷແ͍େֶӃੜͰ͋Γɼ೔ຊͷඪ४తͳԻ੠ύϥϝʔλʹ 1 ࣍ͱ 2 ࣍ͷಈతಛ௃ྔΛՃ͑ͨ΋ͷΛӳ‫ڭޠ‬ҭΛड͚͖ͯͨ࿩ऀͰ͋Δʢ“Monolingual”ʣɽ΋͏‫؍‬ଌϕΫτϧͱ͠ɼ5 ঢ়ଶ left-to-right ‫ܕ‬ͷ HSMM[15] ͷҰਓ͸ɼ1 ೥ؒΦʔετϥϦΞ΁ͷཹֶ‫ݧܦ‬ͷ͋ΔେֶੜֶशΛߦ͏ɽର਺ύϫʔͱϝϧέϓετϥϜ܎਺͸ಉҰεͰ͋Γɼӳ‫ޠ‬शख़౓͕ߴ͍࿩ऀͰ͋Δʢ“Bilingual”ʣɽ্‫ ه‬2 ໊͕ൃ੠ͨ͠ ARCTIC Ի੠σʔλϕʔεதͷ A ηο2ैདྷ๏ [5]ʢͨͩ͠ɼҰରଟ࿩ऀม‫Ͱ׵‬͸ͳ͘೔ຊਓӳ‫ޠ‬Λ༻͍ͨҰରҰ࿩ऀม‫׵‬Λ࢖༻ʣʹ‫͖ͮج‬ɼӳ‫ޠ‬฼‫ޠ‬࿩ऀͷ࿩ऀґଘ
HSMM ͷग़ྗԻ੠ύϥϝʔλʹରͯ͠ɼGMM ʹ‫ͮ͘ج‬౷‫ܭ‬త੠࣭ม‫׵‬Λద༻ⓒ 2015 Information Processing Society of Japanτ 593 จΛదԠσʔλͱͯ͠࢖༻͢Δɽ࿩ऀੑͷධՁͰ͸ɼ໨ඪ೔ຊ‫ޠ‬฼‫ޠ‬࿩ऀͷ೔ຊ‫ޠ‬෼ੳ߹੒Ի੠ΛϦϑΝϨϯεͱͨ͠ 5 ஈ֊ DMOSʢDegradation3Vol.2015-SLP-105 No.3
2015/2/27

৘ใॲཧֶձ‫ڀݚ‬ใࠂ
IPSJ SIG Technical Report

Mean Opinion ScoreʣධՁΛ࣮ࢪ͢ΔɽධՁ͢Δख๏͸ɼϱϱϵϱйŽŶĨŝĚĞŶĐĞŝŶƚĞƌǀĂů

ϵϱйŽŶĨŝĚĞŶĐĞŝŶƚĞƌǀĂů

ؔ͢Δ 5 ஈ֊ MOSʢMean Opinion ScoreʣධՁΛ࣮ࢪ
͢ΔɽධՁ͢Δख๏͸ɼ“ERJ”ɼ“HMM+VC”ɼ“Adapt”ɼ

“Dur.”ɼ“Dur.+Pow.”ɼ“Native”ͷ 6 ͭͰ͋Δɽͳ͓ɼ֤

ϰ

ϰ

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DK^

ͷ 5 ͭͰ͋ΔɽࣗવੑͷධՁͰ͸ɼӳ‫ޠ‬Ի੠ͷࣗવੑʹDK^“ERJ”ɼ“HMM+VC”ɼ“Adapt”ɼ“Dur.”ɼ“Dur.+Pow.”

Ϯ

Ϯ

ϭ

ϭ

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͸ɼ೔ຊ‫ޠ‬฼‫ޠ‬࿩ऀʹΑΔείΞͱൺֱͯ͠ɼେ͖͘‫ݮ‬গਤ 4૬ରతͳείΞͷ্ঢ͕ΈΒΕΔɽ͜ΕΒͷ݁Ռ͸ɼӳ‫ޠ‬ൃ࿩ͷϦζϜ͓Αͼ‫ڧ‬੎ʹରͯ͠ɼӳ‫ޠ‬฼‫ޠ‬࿩ऀ͸೔ຊ‫ޠ‬฼‫ޠ‬࿩ऀΑΓ΋աහͰ͋ΔͨΊͩͱߟ͑ΒΕΔɽ
ͳ͓ɼ྆฼‫ޠ‬࿩ऀʹΑΔࣗવੑʹؔ͢ΔධՁʹ͓͍ͯɼ“Dur.” ͱ “Dur.+Pow.” ͸ଞͷख๏ΑΓ΋ߴ͍είΞΛ֫
ಘ͍ͯ͠Δɽ·ͨɼ࿩ऀੑʹؔ͢ΔධՁʹ͓͍ͯ΋ɼ“Dur.”
ͱ “Dur.+Pow.” ͸ “ERJ”ͱಉ౳ͷ࿩ऀੑΛอ͍࣋ͯ͠Δɽ͜ͷ͜ͱ͔ΒɼఏҊ͢Δӆ཯ิਖ਼๏ͷ༗ޮੑ͕֬ೝͰ͖ΔɽҎ্ͷ݁Ռ͔Βɼ೔ຊ‫ޠ‬฼‫ޠ‬࿩ऀͱӳ‫ޠ‬฼‫ޠ‬࿩ऀͱͷؒʹ͸ධՁ݁Ռʹҧ͍͕ੜ͓ͯ͡Γɼӳ‫ޠ‬฼‫ޠ‬࿩ऀͷํ͕ΑΓӳ‫ൃޠ‬࿩ͷӆ཯ʹରͯ͠හ‫͋Ͱײ‬Δ͜ͱ͕֬ೝͰ͖ɼ·Ƶƌ͘нWŽǁ͘Z:,DDнsĚĂƉƚƵƌ͘Ƶƌ͘нWŽǁ͘Z:,DDнsĚĂƉƚƵƌ͘Ƶƌ͘нWŽǁ͘prosody correction method.
ϱϱϵϱйŽŶĨŝĚĞŶĐĞŝŶƚĞƌǀĂů

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ϰ

ϯ

DK^

ऀʹΑΔධՁͰ͸ɼ೔ຊ‫ޠ‬฼‫ޠ‬࿩ऀʹΑΔධՁͱൺֱͯ͠ɼ

ӆ཯ิਖ਼๏ʹର͢Δ࿩ऀੑʹؔ͢Δओ‫؍‬ධՁ݁ՌDK^

ਤ 5 ʹࣔࣗ͢વੑʹؔ͢ΔධՁ݁Ռʹ͓͍ͯɼӳ‫ޠ‬฼‫ޠ‬࿩DŽŶŽůŝŶŐƵĂů

Fig. 4 Results of subjective evaluation of individuality for͢Δ܏޲͕‫ݟ‬ΒΕΔɽ࣍ʹɼӳ‫ޠ‬฼‫ޠ‬࿩ऀͷύϫʔΛ൓өͨ͠ख๏ʢ“HMM+VC” ͱ “Dur.+Pow.”ʣʹண໨͢Δͱɼ

ŝůŝŶŐƵĂů

;ďͿǀĂůƵĂƚĞĚďǇŶŐůŝƐŚƐƉĞĂŬĞƌƐ

;ĂͿǀĂůƵĂƚĞĚďǇ:ĂƉĂŶĞƐĞƐƉĞĂŬĞƌƐ

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ϵϱйŽŶĨŝĚĞŶĐĞŝŶƚĞƌǀĂů

ϯŝůŝŶŐƵĂů

DŽŶŽůŝŶŐƵĂů

;ĂͿǀĂůƵĂƚĞĚďǇ:ĂƉĂŶĞƐĞƐƉĞĂŬĞƌƐ
ਤ 5

Z:,DDнsĚĂƉƚƵƌ͘Ƶƌ͘нWŽǁ͘EĂƚŝǀĞ

(a) ͱ (b) ͷൺֱ͔Βɼӳ‫ޠ‬฼‫ޠ‬࿩ऀʹΑΔࣗવੑͷείΞDŽŶŽůŝŶŐƵĂů

Z:,DDнsĚĂƉƚƵƌ͘Ƶƌ͘нWŽǁ͘EĂƚŝǀĞ

͢Δɽਤ 4 ͷ (a) ͱ (b) ͷൺֱ͔Βɼ࿩ऀੑͷείΞ͸ɼҟͳΔ฼‫ޠ‬Λ࣋ͭධՁऀؒͰಉఔ౓Ͱ͋ΔҰํͰɼਤ 5 ͷŝůŝŶŐƵĂů

Z:,DDнsĚĂƉƚƵƌ͘Ƶƌ͘нWŽǁ͘EĂƚŝǀĞ

ʢ“ERJ” ͱ “Adapt”ʣʹ͓͚ΔධՁऀͷ฼‫ޠ‬ͷӨ‫ʹڹ‬ண໨Z:,DDнsĚĂƉƚƵƌࣗ͘વੑʹؔ͢ΔධՁ݁ՌΛࣔ͢ 3 ɽ·ͣɼิਖ਼ແ͠ͷख๏Ƶƌ͘нWŽǁ͘ਤ 4 ͱਤ 5 ʹͦΕͧΕɼӆ཯ิਖ਼๏ʹର͢Δ࿩ऀੑͱZ:,DDнsĚĂƉƚƵƌ͘Ƶƌ͘нWŽǁ͘EĂƚŝǀĞ

‫ͼٴޠ‬ӳ‫ޠ‬฼‫ޠ‬࿩ऀ֤ 6 ໊ʹΑΓ࣮ࢪ͢Δɽ

Z:,DDнsĚĂƉƚƵƌ͘ධՁ͸ɼ໨ඪ࿩ऀຖʹ࡞੒࣮ͨ͠‫ݧ‬ηοτΛ༻͍ͯɼ೔ຊ

ŝůŝŶŐƵĂů

DŽŶŽůŝŶŐƵĂů

;ďͿǀĂůƵĂƚĞĚďǇŶŐůŝƐŚƐƉĞĂŬĞƌƐ

ӆ཯ิਖ਼๏ʹର͢Δࣗવੑʹؔ͢Δओ‫؍‬ධՁ݁Ռ

Fig. 5 Results of subjective evaluation of naturalness for
prosody correction method.

‫ޠ‬࿩ऀ 6 ໊ʹΑΓ࣮ࢪ͢ΔɽͨɼఏҊ๏ʹΑΔ‫ܧ‬ଓ௕‫ͼٴ‬ύϫʔิਖ਼ʹΑΓɼ೔ຊ‫ޠ‬฼

ਤ 7 ʹɼӳ‫ޠ‬शख़౓ʢ“High” ͱ “Low”ʣຖʹू‫ͨ͠ܭ‬ɼ‫ޠ‬࿩ऀͷ࿩ऀੑΛอ࣋ͭͭ͠ɼӳ‫ޠ‬฼‫ޠ‬࿩ऀʹͱͬͯࣗવ

ӆ཯ิਖ਼๏ʹର͢Δ࿩ऀੑͱࣗવੑʹؔ͢Δओ‫؍‬ධՁ݁Ռੑͷߴ͍ӳ‫ޠ‬Ի੠Λ߹੒Ͱ͖Δ͜ͱ͕෼͔ΔɽΛࣔ͢ɽ·ͣ࿩ऀੑʹؔ͢ΔධՁ݁Ռʹ͓͍ͯɼGMM ੠࣭

4.2.2 ӆ཯ิਖ਼๏ʹ͓͚Δൃ࿩ऀͷӳ‫ޠ‬शख़౓ͷӨ‫ڹ‬ม‫׵‬Λར༻ͨ͠ख๏ “HMM+VC”ʹண໨͢Δͱɼ“Low”ʹదԠσʔλ͸ɼ೔ຊਓֶੜʹΑΔಡΈ্͛ӳ‫ޠ‬Ի੠σʔରͯ͠ɼશϞσϧύϥϝʔλΛదԠͨ͠ख๏ “Adapt”ͱൺ

λϕʔε [8] தͷ࠷ߴʢ
ʠHighʡ
ʣ΋͘͠͸࠷௿ʢ
ʠLowʡ
ʣӳ‫ޠ‬

ֱͯ͠ɼ࿩ऀੑ͕େ͖͘ྼԽ͢Δ܏޲͕‫ݟ‬ΒΕΔɽ“High”शख़౓είΞΛ࣋ͭஉঁ‫ ܭ‬4 ໊ʹΑΔ TIMIT[17] 60 จͱʹ͓͍ͯ΋ɼྼԽͷఔ౓͸খ͘͞ͳΔ͕ɼಉ༷ͷ܏޲͕‫ݟ‬

͢Δɽͨͩ͠ɼຊߘͷӳ‫ޠ‬शख़౓͸ɼσʔλϕʔεதͰఆٛΒΕΔɽҰํͰɼఏҊ๏ͷ‫ܧ‬ଓ௕͓ΑͼύϫʔΛิਖ਼ͨ͠͞Ε͍ͯΔෳ਺ͷ‫ج‬४ʢԻૉੜ੒ɼϦζϜ౳ʣʹ͓͚Δධఆ

“Dur.+Pow.”ʹؔͯ͠͸ɼӳ‫ޠ‬शख़౓ʹؔ܎ͳ͘ “Adapt”

఺ͷฏ‫ۉ‬Λࢦ͢ɽධՁ๏͸ 4.2.1 અͱಉ༷ʢͨͩ͠ɼ࿩ऀੑ

ͱಉ౳ͷ࿩ऀੑΛอ͍ͬͯΔ͜ͱ͕෼͔ΔɽͷධՁͰ͸ɼ໨ඪ೔ຊ‫ޠ‬฼‫ޠ‬࿩ऀͷ೔ຊਓӳ‫ޠ‬෼ੳ߹੒Ի

࣍ʹɼࣗવੑʹؔ͢ΔධՁ݁ՌΛ‫ݟ‬Δͱɼ“HMM+VC”

੠ΛϦϑΝϨϯεͱ͢Δ఺ͷΈҟͳΔʣͰ͋Γɼ࿩ऀੑͷධͱൺֱ͠ɼ“Adapt”͸”Low”ʹ͓͍ͯେ෯ͳྼԽΛੜ͡͞ՁͰ͸ “HMM+VC”ɼ“Adapt”ɼ“Dur.+Pow.” ͷ 3 ͭɼࣗͤΔ͜ͱ͕෼͔Δɽ͜Εʹର͠ɼ“Dur.+Pow.”͸ɼӆ཯ิવੑͷධՁͰ͸ “HMM+VC”ɼ “Adapt”ɼ “Dur.+Pow.”ɼ

ਖ਼ʹΑΓࣗવੑྼԽΛ๷͙͜ͱ͕ՄೳͰ͋Γɼӳ‫ޠ‬शख़౓

“Native” ͷ 4 ͭͷख๏ΛධՁ͢Δɽͳ͓ɼ֤ධՁ͸ɼશ೔ʹؔ܎ͳ͘ “HMM+VC”ͱಉ౳ͷࣗવੑ͕ಘΒΕΔ͜ͱ͕ຊ‫ޠ‬฼‫ޠ‬࿩ऀͷԻ੠Λ‫ؚ‬Μ࣮ͩ‫ݧ‬ηοτΛ༻͍ͯɼӳ‫ޠ‬฼෼͔ΔɽҎ্ͷ݁Ռ͔Βɼӳ‫ޠ‬शख़౓ʹؔΘΒͣɼఏҊ๏͕‫݈ؤ‬

3ͨͩ͠ɼਤ 4 (a) ͱਤ 5 (a) ͸ [9] ͷ࠶‫͋Ͱܝ‬Δɽ

ⓒ 2015 Information Processing Society of Japan

ʹಈ࡞͢Δ͜ͱΛ֬ೝͰ͖ɼ‫ܧ‬ଓ௕‫ͼٴ‬ύϫʔิਖ਼ʹΑΓɼ

4

Vol.2015-SLP-105 No.3
2015/2/27

৘ใॲཧֶձ‫ڀݚ‬ใࠂ
IPSJ SIG Technical Report

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֤छ߹੒Ի੠ͷεϖΫτϩάϥϜʢൃ࿩จதͷ “consonants”ͱ͍͏୯‫ʹޠ‬ରԠʣͷྫɽਤ 74 ໊ʹΑΔ TIMIT 60 จͱ͢Δɽ࿩ऀੑͷධՁͰ͸ɼ೔ຊ‫ޠ‬฼‫ޠ‬࿩ऀͷ೔ຊਓӳ‫ޠ‬෼ੳ߹੒Ի੠ΛϦϑΝϨϯεͱ͠>ŽǁͨϓϦϑΝϨϯεςετ (XAB ςετ) Λ࣮ࢪ͢ΔɽධՁ,ŝŐŚ͢Δख๏͸ɼ“Dur.+Pow.”ɼ“Dur.+Pow.+UVC”ͷ 2 ͭͰ;ĂͿ/ŶĚŝǀŝĚƵĂůŝƚǇ
ਤ 8

,ŝŐŚ

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EĂƚŝǀĞ

EĂƚŝǀĞ

ϬƵƌ͘нWŽǁ͘จɼฒͼʹɼ4.2.2 અͷ “High” ΋͘͠͸ “Low” ʹଐ͢ΔϬ͘ϮƵƌ͘нWŽǁ͘нhsϬ͸ɼ“Dur.+Pow.”ɼ“Dur.+Pow.+UVC”ɼ“Native”ͷ 3 ͭƵƌ͘нWŽǁ͘

Ϭ͘ϰ

Ϭ͘ϰ

gual” ʹΑΔ ARCTIC Ի੠σʔλϕʔεதͷ A ηοτ 60ϑΝϨϯεςετ (AB ςετ) Λ࣮ࢪ͢ΔɽධՁ͢Δख๏

EĂƚŝǀĞ

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͋ΔɽࣗવੑͷධՁͰ͸ɼӳ‫ޠ‬Ի੠ͷࣗવੑʹؔ͢ΔϓϦ

ĚĂƉƚ

Ϭ͘ϴ

Ϭ͘ϴ

దԠσʔλ͸ɼ 4.2.1 અͷ “Monolingual” ‫“ ͼٴ‬Bilin-ϵϱйŽŶĨŝĚĞŶĐĞŝŶƚĞƌǀĂů

EĂƚŝǀĞ

4.3 ແ੠ࢠԻεϖΫτϧஔ‫ʹ׵‬ΑΔԻӆิਖ਼ͷޮՌϭϵϱйŽŶĨŝĚĞŶĐĞŝŶƚĞƌǀĂů

WƌĞĨĞƌĞŶĐĞƐĐŽƌĞ

౓ͷ௿͍࿩ऀʹ͓͍ͯಛʹ༗ޮͰ͋Δ͜ͱ͕෼͔Δɽӳ‫ޠ‬शख़౓ຖʹ‫ͨ͠ࢉܭ‬ओ‫؍‬ධՁ݁Ռʢӆ཯ิਖ਼๏ʣ

(prosody correction method).
ϭ೔ຊਓӳ‫ޠ‬ͷ࿩ऀੑΛอ࣋ͭͭ͠ɼࣗવੑͷߴ͍ӳ‫ޠ‬Ի੠Λ߹੒Ͱ͖Δ͜ͱ͕෼͔Δɽ·ͨɼิਖ਼ޮՌ͸ɼӳ‫ޠ‬शख़>Žǁ;ďͿEĂƚƵƌĂůŶĞƐƐ

WƌĞĨĞƌĞŶĐĞƐĐŽƌĞ

for a word fragment “consonants”,ŝŐŚFig. 7 Results calculated in each English proﬁciency levelƵƌ͘нWŽǁ͘нhs

Fig. 6 Example of spectrograms of synthetic speech samples>Žǁ;ĂͿ/ŶĚŝǀŝĚƵĂůŝƚǇ

Ƶƌ͘нWŽǁ͘ਤ 6,DDнs

68Ƶƌ͘нWŽǁ͘,DDнs

ϯƵƌ͘нWŽǁ͘нhsEĂƚŝǀĞ

02
4

ϰ,DDнs

68

ϰϵϱйŽŶĨŝĚĞŶĐĞŝŶƚĞƌǀĂů

Ƶƌ͘нWŽǁ͘24

ϱ

ϵϱйŽŶĨŝĚĞŶĐĞŝŶƚĞƌǀĂů

DK^Ƶƌ͘нWŽǁ͘нhs0ϱƵƌ͘нWŽǁ͘

Ɛ

ĚĂƉƚ

ƚ

Ƶƌ͘нWŽǁ͘нhs

2
4
6
8

Ŷ

,DDнs

0ĂǆƵƌ͘нWŽǁ͘ƐĂǆ ŶƵƌ͘нWŽǁ͘

ĚĂƉƚ

Ŷ

Ƶƌ͘нWŽǁ͘

ĂĂ

DK^

&ƌĞƋƵĞŶĐǇ΀Ŭ,ǌ΁Frequency (kHz)Frequency (kHz)Frequency (kHz)Ŭ>Žǁ;ďͿEĂƚƵƌĂůŶĞƐƐ

ӳ‫ޠ‬शख़౓ຖʹ‫ͨ͠ࢉܭ‬ओ‫؍‬ධՁ݁ՌʢԻӆิਖ਼๏ʣ

Fig. 8 Results calculated in each English proﬁciency level(phoneme correction method).

Ͱ͋Δɽ֤ධՁ͸ɼશͯͷ೔ຊ‫ޠ‬฼‫ޠ‬࿩ऀͷԻ੠Λ‫ؚ‬Μͩ

“Dur.+Pow.+UVC”͸ “Dur.+Pow.”ͱಉ౳ͷࣗવੑ‫ͼٴ‬࣮‫ݧ‬ηοτΛ༻͍ͯɼӳ‫ޠ‬฼‫ޠ‬࿩ऀ 6 ໊ʹΑΓ࣮ࢪ͢Δɽ࿩ऀੑΛอ࣋Ͱ͖Δ͜ͱ͕෼͔Δɽͳ͓ɼ“Dur.+Pow.”ͱ

ͨͩ͠ɼධՁ݁Ռ͸ӳ‫ޠ‬शख़౓ຖʹ‫͠ࢉܭ‬ɼ“Monolingual”“Dur.+Pow.+UVC”ʹର͠ɼt ‫ݕ‬ఆΛߦͬͨͱ͜Ζɼ“Low”

ͱ “Bilingual” ͸ͦΕͧΕɼ“Low” ͱ “High” ʹଐ͢Δ΋ͷࣗવੑͷΈ༗ҙ͕ࠩ֬ೝ͞Εͨʢp < .01ʣɽͷͱ͢Δɽ
ਤ 6 ʹɼ֤ख๏ʹΑΔεϖΫτϧάϥϜͷྫΛࣔ͢ɽਤ͔Βɼ“Native”ͱൺֱ͠ɼ“Dur.+Pow.”Ͱ͸ແ੠ࢠԻ෦෼

Ҏ্ͷ݁Ռ͔Βɼӆ཯ิਖ਼๏ͱಉ༷ʹɼఏҊͨ͠Իӆิਖ਼๏΋ࣗવੑվળʹ༗ޮͰ͋Γɼಛʹӳ‫ޠ‬शख़౓ͷ௿͍࿩ऀʹ͓͍ͯ༗ޮͰ͋Δ͜ͱ͕෼͔Δɽʢ/s/ͳͲʣʹ͓͍ͯɼಛʹߴप೾਺ྖҬʹ͓͚ΔεϖΫτ
ϧแབྷͷ‫ܗ‬ঢ়͕େ͖͘ҟͳΔ͜ͱ͕෼͔Δɽ͜Ε͸ɼύ

4.4 ໌ྎੑʹؔ͢ΔධՁϫʔิਖ਼Λ࣮ࢪͨ͠ࡍʹɼҟԻΛੜͤ͡͞ΔཁҼͱͳΔɽఏҊ๏ʹରͯ͠ɼ໌ྎੑʹؔ͢Δॻ͖औΓࢼ‫ݧ‬Λ࣮ࢪ͜Εʹର͠ɼ“Dur.+Pow.+UVC”Ͱ͸ɼ“Native”ಉ༷ͷε͢ΔɽධՁσʔλ͸ SUS[18] 50 จͱ͠ɼධՁ͢Δख๏͸ɼϖΫτϧแབྷ‫ܗ‬ঢ়͕ಘΒΕΔͨΊɼύϫʔิਖ਼ʹΑΔѱӨ

“HMM+VC”ɼ“Dur.+Pow.+UVC”ɼ“Native”ͷ 3 ͭͰ͋‫ڹ‬Λ؇࿨͢Δ͜ͱ͕Ͱ͖ɼࣗવੑͷ޲্͕‫ظ‬଴Ͱ͖Δɽ

Δɽͳ͓ɼ֤ධՁ͸ɼશ೔ຊ‫ޠ‬฼‫ޠ‬࿩ऀͷԻ੠Λ‫ؚ‬Μ࣮ͩ

ਤ 8 ʹɼӳ‫ޠ‬शख़౓ʢ“High” ͱ “Low”ʣຖʹू‫͠ܭ‬‫ݧ‬ηοτΛ༻͍ͯɼӳ‫ޠ‬฼‫ޠ‬࿩ऀ 6 ໊ʹΑΓ࣮ࢪ͢ΔɽͨͨɼԻӆิਖ਼๏ʹର͢Δ࿩ऀੑͱࣗવੑʹؔ͢Δओ‫؍‬ධՁͩ͠ɼධՁ݁Ռ͸ӳ‫ޠ‬शख़౓ຖʹ‫͠ࢉܭ‬ɼ“Monolingual”

݁ՌΛࣔ͢ɽ“Low”ʹண໨͢Δͱɼ“Dur.+Pow.+UVC”͸

ͱ “Bilingual” ͸ͦΕͧΕɼ“Low” ͱ “High” ʹଐ͢Δ΋“Dur.+Pow.”ͱൺֱͯ͠ɼ࿩ऀੑΛಉ౳ఔ౓ʹอ࣋ͭͭ͠

ͷͱ͢ΔɽࣗવੑΛվળͰ͖Δ͜ͱ͕෼͔Δɽ·ͨɼ“High”ʹ͓͍ͯɼⓒ 2015 Information Processing Society of Japanਤ 9 ʹɼӳ‫ޠ‬शख़౓ʢ“High” ͱ “Low”ʣຖʹू‫͠ܭ‬5

Vol.2015-SLP-105 No.3
2015/2/27

৘ใॲཧֶձ‫ڀݚ‬ใࠂϴϱtŽƌĚĐŽƌƌĞĐƚ
tŽƌĚĐŽƌƌĞĐƚƌĂƚĞtŽƌĚĂĐĐƵƌĂĐǇ
tŽƌĚĂĐĐƵƌĂĐǇ

ϴϬ

[4]

ϳϱ
ϳϬ

ਤ 9

EĂƚŝǀĞ

Ƶƌ͘нWŽǁ͘нhsƵƌ͘нWŽǁ͘нhs,ŝŐŚ,DDнs

[5]ϲϱ,DDнs

ZĞĐŽŐŶŝƚŝŽŶƌĞƚĞ΀й΁

IPSJ SIG Technical Report

[6]

>Žǁ

ӳ‫ޠ‬शख़౓ຖʹ‫ྎ໌ͨ͠ࢉܭ‬ੑʹؔ͢Δॻ͖औΓࢼ‫݁ݧ‬Ռ

Fig. 9 Results of dictation test on intelligibility calculated in[7]each English proﬁciency level.

ͨ ɼॻ ͖ औ Γ ࢼ ‫ ݁ ݧ‬Ռ Λ ࣔ ͢ ɽ“Low”ʹ ண ໨ ͢ Δ ͱ ɼ[8]“Dur.+Pow.+UVC”͸ “HMM+VC”ͱൺֱͯ͠ɼ໌ྎੑ
͕վળ͍ͯ͠Δ͜ͱ͕෼͔Δɽ͜Ε͸ɼ“HMM+VC”ʹର͠ɺ“Dur.+Pow.+UVC”͕࣋ͭԻӆิਖ਼ޮՌʹΑΓɼແ੠[9]ࢠԻԻૉͷ໌ྎੑ͕ճ෮ͨͨ͠Ίͩͱߟ͑ΒΕΔɽ·ͨɼ

“High”ʹ͓͍ͯ͸ɼ“Dur.+Pow.+UVC”͸ “HMM+VC”
ͱಉ౳ͷ໌ྎੑͰɼ“Low”ΑΓ΋ߴ͍໌ྎੑ͕ಘΒΕ͍ͯ

[10]Δɽͳ͓ɼ“Dur.+Pow.+UVC”͸ɼ“Native”ͱൺֱ͢Δͱɼ୯‫ޠ‬ਖ਼ղਫ਼౓ͷྼԽΛ “High”ʹ͓͍ͯ໿ 5 ˋɼ“Low”ʹ͓͍ͯ໿ 8 ˋʹͱͲΊΔ͜ͱ͕Ͱ͖Δɽ[11]

5. ͓ΘΓʹ
ຊߘͰ͸ɼ೔ຊਓӳ‫ޠ‬Ի੠߹੒ʹ͓͚Δ࿩ऀੑΛอ࣋͠[12]ͨࣗવੑվળΛ໨తͱͯ͠ɼϞσϧదԠʹΑΔӆ཯ิਖ਼๏ʹରͯ͠ɼධՁऀͷ฼‫ൃͱޠ‬࿩ऀͷӳ‫ޠ‬शख़౓͕༩͑ΔӨ

[13]‫͍ͯͭʹڹ‬ௐࠪ͠ɼ·ͨɼࢠԻεϖΫτϧิਖ਼ʹΑΔԻӆิਖ਼๏ΛఏҊͨ͠ɽ࣮‫ݧ‬తධՁʹΑΓɼʢ̍ʣύϫʔิਖ਼ʹ[14]

ΑΔࣗવੑͷվળޮՌ͸ɼӳ‫ޠ‬฼‫ޠ‬࿩ऀʹΑΔධՁʹ͓͍ͯ‫ݦ‬ஶͰ͋Δ͜ͱɼʢ̎ʣӳ‫ޠ‬शख़౓ʹؔΘΒͣɼӆ཯ิਖ਼๏ʹΑΓࣗવੑ͕վળ͢Δ͜ͱɼ
ʢ̏ʣԻӆิਖ਼๏΋ࣗવੑվળʹ༗ޮͰ͋Δ͜ͱΛࣔͨ͠ɽࠓ‫ޙ‬͸ɼ໨ඪ࿩ऀຖͷԻӆ‫ޡ‬Γʹ‫࠷ͮ͘ج‬దͳิਖ਼๏Λ‫ݕ‬౼͢Δඞཁ͕͋Δɽँࣙ ຊ‫ڀݚ‬ͷҰ෦͸ɼʢಠʣ৘ใ௨৴‫ߏػڀݚ‬ͷҕୗ‫ݚ‬‫ڀ‬ʮ஌ࣝɾ‫ޠݴ‬άϦουʹ‫ͮ͘ج‬ΞδΞҩྍަྲྀࢧԉγεςϜͷ‫ڀݚ‬։ൃʯ͓Αͼ JSPS Պ‫ݚ‬අ 26280060 ͷॿ੒Λड͚࣮ࢪͨ͠΋ͷͰ͋Δɽ

[15]

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