2-2-7ෳ߹΢ΣʔϒϨοτϞσϧ෼ੳ߹੒‫ ͮ͘جʹܥ‬HMM Ի੠߹੒∗ˑ๺৚৳ࠀ 1 ɼ˚ೆ‫ݡ‬ଠ࿠ 2 ɼ ᜊ౻େี 1 ɼ ُԬ߂࿨ 1,3 ɼ ࠧեࢁໜथ 1(1 ౦େ ৘ใཧ޻, 2 ౦େ ޻, 3 NTT CS ‫)ݚ‬1͸͡ΊʹຊߘͰ͸ɼHMM Ի੠߹੒ʹ͓͍ͯɼͦͷԻ੠෼ੳ߹੒‫ͯ͠ͱܥ‬ෳ߹΢ΣʔϒϨοτϞσϧ (CompositeWavelet Model; CWM) [1] Λ༻͍Δख๏ΛఏҊ͢ΔɽCWM Ͱ͸ɼࠞ߹Ψ΢εؔ਺Ϟσϧ (GaussianMixture Model; GMM) ʹΑΓεϖΫτϧแབྷΛۙࣅ͠ɼԻ੠ͷಛ௃Λ GMM ͷύϥϝʔλͰද‫͢ݱ‬ΔʢҎԼ CWM ύϥϝʔλʣɽ߹੒࣌ʹ͸ɼCWM ύϥϝʔλʹ‫ ͍ͯͮج‬Gabor wavelet Λੜ੒͠ɼϐονप‫Ͱظ‬ॏͶ߹ΘͤΔ͜ͱͰԻ੠೾‫ܗ‬Λ߹੒͢ΔɽຊߘͰ͸ɼCWM ύϥϝʔλΛಛ௃ྔͱ͠ɼͦΕʹ‫ͮج‬͘೾‫ܗ‬ੜ੒Λߦ͏ HMM Ի੠߹੒ʹ͍ͭͯٞ࿦͢Δɽର࿩ௐͷԻ੠΍‫ײ‬৘Ի੠ͱ͍ͬͨଟ༷ͳԻ੠ͷ߹੒Λ࣮‫͢ݱ‬Δ্Ͱ͸ɼՃ޻ੑʹ༏Εͨ߹੒ख๏͕๬·ΕΔɽԻ੠ͷಛ௃͕ύϥϝτϦοΫͳϞσϧͰද‫͞ݱ‬ΕͨԻ੠߹੒๏͸ɼύϥϝʔλͷૢ࡞ʹΑͬͯ߹੒Իͷॊೈͳૢ࡞͕ՄೳͰ͋Δɽྫ͑͹ LPCɼPARCORɼLSP [2]ɼϝϧέϓετϥϜ߹੒ [3] ͳͲͷύϥϝτϦοΫͳԻ੠߹੒ख๏͸ɼԻ੠ූ߸ԽͷଞɼHMM Ի੠߹੒ʹ͓͚Δ෼ੳ߹੒‫ͯ͠ͱܥ‬ར༻͞ΕΔɽ্ड़ͷύϥϝτϦοΫͳ෼ੳͰಘΒΕΔಛ௃ྔ͸εϖΫτϧแབྷͷද‫ʹݱ‬ҧ͍͕͋ΔɽLSP ͸ɼεϖΫτϧͷप೾਺ํ޲ͷؔ܎ʹண‫ͨ͠؟‬ಛ௃ද‫͋Ͱݱ‬ΓɼϑΥϧϚϯτप೾਺ͱຌͦରԠ͍ͯ͠Δɽ͜ͷͨΊύϥϝʔλͷิؒಛੑʹ༏Ε͓ͯΓɼ·ͨ౷‫ܭ‬తֶशʹ൐͏εϖΫτϧฏ‫׈‬ԽͷӨ‫͕ڹ‬গͳ͍ɽ͔͠͠ɼ౷‫ܭ‬తֶश‫ʹޙ‬ಘΒΕͨύϥϝʔλ͕҆ఆੑ৚݅Λຬͨ͢อূ͕ͳ͘ɼߏ੒͞ΕͨϑΟϧλ͕ෆ҆ఆʹͳΔ໰୊͕಺ࡏ͢ΔɽҰํɼϝϧέϓετϥϜʹ୅ද͞ΕΔέϓετϥϜ‫ܕ‬ͷಛ௃ྔ͸ɼεϖΫτϧแབྷͷৼ෯ʹண‫ͨ͠؟‬ಛ௃ͱ͍͑Δɽಛ௃ྔͷ࣍‫ؒݩ‬ͷಠཱੑ͕ߴ͘ɼΨ΢ε෼෍Λग़ྗ෼෍ͱ͢ΔΑ͏ͳ౷‫ܭ‬తֶशʹద͍ͯ͠Δ൓໘ɼֶशʹͱ΋ͳ͏εϖΫτϧͷฏ‫׈‬Խ͕‫ݦ‬ஶͳ໰୊ͷҰͭͰ͋ΔɽLSP ΍ϝϧέϓετϥϜΛ༻͍ͨ HMM Ի੠߹੒͸ɼۙ೥Ͱ͸೾‫઀ܗ‬ଓ‫ܕ‬Ի੠߹੒ͱಉ౳Ҏ্ͷྃղ౓ͷԻ੠Λ߹੒ՄೳͰ͋Δ [4]ɽ͔͠͠߹੒Ի੠ͷࣗવੑʹ͍ͭͯ͸ɼվળͷ༨஍͕͋Δɽ͜ΕΒͷύϥϝτϦοΫͳԻ੠߹੒ͷଟ͘͸८ճ‫ܕ‬ϑΟϧλΛ༻͍ͨख๏Ͱ͋Γɼ͜ΕΒͷख๏Ͱ͸ϑΟϧλͷ࣌ؒಛੑʹؔ͢Δ໰୊͕ࢦఠ͞Ε͍ͯΔ [1]ɽΛຊ‫Ͱڀݚ‬͸ɼLSPɼϝϧέϓετϥϜͷ૒ํͷಛ௃ྔͷར఺Λ౷߹ՄೳͰ͋Γɼ͔ͭ८ճ‫ܕ‬ϑΟϧλͷ໰୊఺Λղܾ͠͏Δख
๏ͱͯ͠ɼCWM ෼ੳʹΑͬͯಘΒΕΔಛ௃ྔΛ༻͍ͨ HMM Ի੠߹੒ʹؔͯ͠ɼͦͷ‫ݕ‬౼Λߦͬͨɽ∗

2CWM ෼ੳ߹੒‫ܥ‬

2.1ෳ߹΢ΣʔϒϨοτϞσϧ (CWM)८ճ‫ܕ‬ϑΟϧλͰ͸ɼ‫ৼڞ‬ಛੑͷ Q ஋͕ߴ͍ϑΟϧλΛഒԻ੒෼͕‫ৼڞ‬प೾਺ͱҰக͢ΔԻ‫ʹݯ‬Αͬͯ‫ۦ‬ಈͨ͠৔߹ɼ੍࣌ؒ‫ޚ‬ಛੑͷѱ͍Ի੠͕ੜ੒͞ΕΔ͜ͱͰɼ‫ޙ‬ଓԻʹѱӨ‫ڹ‬Λ༩͑ɼࣗવੑྼԽͷҰҼͱͳΔ [1]ɽCWM ʹ‫ͮ͘ج‬෼ੳ߹੒͸ɼ͜ͷ໰୊Λղܾ͠͏Δ FIR ϑΟϧλʹΑΔ߹੒ख๏Ͱ͋Δ [1]ɽCWM Ͱ͸ɼ࣌ؒྖҬʹ͓͚Δ Gabor wavelet ͱप೾਺ྖҬʹ͓͚ΔΨ΢εؔ਺ͷؔ܎ʹண‫͠؟‬ɼεϖΫτϧแབྷΛ GMM ʹΑͬͯද‫Ͱ্ͨ͠ݱ‬ɼͦΕʹରԠ͢Δॏ৞͞Εͨ Wavelet ؔ਺Λ‫ج‬ຊ೾‫ͯ͠ͱܗ‬ɼϐονप‫ظ‬ຖʹॏͶ߹ΘͤΔ͜ͱͰ߹੒Λ࣮‫͢ݱ‬Δɽ
·ͨ CWM Ͱ͸εϖΫτϧแབྷ͕ GMM Ͱۙࣅ͞ΕΔͨΊɼLSP ͕ද‫͢ݱ‬Δप೾਺ํ޲ͷؔ܎ੑͱέϓετϥϜ͕ද‫͢ݱ‬Δৼ෯ํ޲ͷؔ܎ੑΛಉ࣌ʹϞσϧԽ͍ͯ͠ΔͱղऍͰ͖ɼ૒ํͷಛ௃ྔͷར఺Λ౷߹͠͏Δɽ

2.2

CWM ʹΑΔԻ੠෼ੳຊষͰ͸ɼCWM Λ༻͍ͨԻ੠෼ੳ‫ͼٴ‬෼ੳʹΑͬͯಘΒΕͨύϥϝʔλ͔Βͷ೾‫ܗ‬ੜ੒ʹ͍ͭͯड़΂Δ [1]ɽCWM Ͱ͸ɼԻ੠εϖΫτϧแབྷ GMM Ͱۙࣅ͠ɼ͜ͷύϥϝʔλ͕εϖΫτϧแབྷͷಛ௃ྔද‫ݱ‬ͱΈͳ͞ΕΔɽ͜ͷࡍɼิॿؔ਺๏ʹΑͬͯεϖΫτϧแབྷͱ GMM ʹΑΔϞσϧεϖΫτϧͱͷؒͷ‫ڑ‬཭ई౓Λஞ࣍తʹ࠷খԽ͢Δ͜ͱͰɼεϖΫτϧύϥϝʔλ͕நग़͞ΕΔɽຊ‫Ͱڀݚ‬͸‫཭ڑ‬ई౓ͱͯ͠ɼ
I-divergence

I(Y |F ) =ω,t[Yω,t logYω,t− Yω,t + Fω,t ]Fω,t(1)Λ༻͍ͨɽͨͩ͠ Yω,t ɼFω,t ͸, ͦΕͧΕ࣌ࠁ t ʹ͓͚Δ‫؍‬ଌ͓ΑͼϞσϧεϖΫτϧแབྷΛද͢. Fω,t ͸ҎԼͷΑ͏ͳ GMM Ͱද‫͞ݱ‬ΕΔɽFω,t =w(ω − μk )2
 k exp −2σk2
2πσk2
k=1K
(2)

K ͸ GMM ͷࠞ߹਺Λද͠ɼຊߘͰ͸ҎԼ͜ΕΛ
CWM ͷࠞ߹਺ͱ‫Ϳݺ‬ɽ࠷ऴతʹಘΒΕͨ CWM ύϥϝʔλ μk , σk , wk (k = 1, . . . , K) Λ࿈݁ͨ͠΋ͷ͕εϖΫτϧಛ௃ྔͱͳΔɽͳ͓ɼຊ‫Ͱڀݚ‬͸‫؍‬ଌεϖΫτϧΛ STRAIGHT ෼ੳʹΑΓಘΒΕͨεϖΫτ
ϧͱ͠ɼGMM ਪఆͷࡍͷ μk ͷॳ‫ظ‬஋ͱͯ͠ɼ2K
࣍ͷ LSP ղੳʹΑͬͯಘΒΕͨεϖΫτϧରͷฏ‫ۉ‬Λ༻͍ͨɽ

HMM-based speech synthesis using speech analysis based on Composite Wave Modelɽby HOJONobukatsu, MINAMI Kentaro, SAITO Daisuke, KAMEOKA Hirokazu, and SAGAYAMA Shigeki (TheUniversity of Tokyo)

日本音響学会講演論文集- 287 -

2012年9月

Fig. 1 Ի ૉ/e/ͷ ε ϖ Ϋ τ ϧ แ བྷ ۙ ࣅ;(K=10)ɼ24 ࣍ϝϧέϓετϥϜ

CWMFig. 1 ʹஉ੠࿩ऀ͕ൃ੠ͨ͠ʮ͋ΒΏΔ‫࣮ݱ‬Λ. . . ʯͷԻૉ/e/ͷத৺෦෼ͷεϖΫτϧแབྷɼK = 10 ͷ
CWM Λ༻͍ͨϞσϧεϖΫτϧɼ͓Αͼ 24 ࣍ͷϝϧέϓετϥϜʹΑΔεϖΫτϧแབྷۙࣅΛࣔ͢ɽ
Fig. 1 ͔Β͸ɼϝϧέϓετϥϜͱൺֱ͢Δͱ௿प೾ྖҬͷۙࣅਫ਼౓͸ྼΔ΋ͷͷɼCWM ͸εϖΫτϧแབྷશମΛ؇΍͔ʹۙࣅ͍ͯ͠Δ͜ͱ͕֬ೝ͞ΕΔɽ
2.3

CWM Ի੠೾‫߹ܗ‬੒

CWM ಛ௃ྔͱ‫ج‬ຊप೾਺৘ใΛ༻͍ͯɼԻ੠೾
‫ܗ‬Λ߹੒͢Δख๏ʹ͍ͭͯड़΂Δ. 2.1 અͰ‫ͨ͛ڍ‬८ճ‫ܕ‬ϑΟϧλͷ໰୊఺Λղܾ͢Δํ๏ͱͯ͠ɼGMMแབྷۙࣅͷ‫ٯ‬ϑʔϦΤม‫͔׵‬ΒಘΒΕΔ FIR ‫ܕ‬ϑΟϧλΛ༻͍Δ.
༗੠Ի෦෼Ͱ͸ɼࣜ (3) Ͱࣔ͞ΕΔΑ͏ʹΨ΢εؔ਺ͷ‫ٯ‬ϑʔϦΤม‫͕׵‬ΨϘʔϧؔ਺ɼͭ·ΓΨ΢εؔ਺ͱࡾ֯ؔ਺ͷੵͰ͋Δ͜ͱΛߟྀ͢ΔͱɼGMMͷ‫ٯ‬ϑʔϦΤม‫׵‬͸ΨϘʔϧؔ਺ͷॏͶ߹ΘͤͰද‫͞ݱ‬ΕΔ [1]ɽ

11σ 2 t2(ω − μ)2√⇔
exp−+jμt(3)exp −2σ 22π22πσ࣌ؒྖҬʹ͓͍ͯ Gabor wavelet Λ‫ج‬ຊप೾਺ʹରԠ͢Δִ࣌ؒؒͰฒ΂Δ͜ͱʹΑΓ༗੠Ի෦෼ͷ೾‫߹͕ܗ‬੒͞ΕΔɽ͜Ε͸ FIR ϑΟϧλΛ‫ج‬ຊप೾਺ʹରԠͨ͠σϧλྻͰ‫ۦ‬ಈ͢Δ͜ͱʹ૬౰͢Δ. ແ੠Ի෦෼Ͱ͸ɼCWM ύϥϝʔλ͔ΒಘΒΕͨεϖΫτϧแབྷͷ֤प೾਺ bin ʹཚ਺Λֻ͚߹ΘͤɼྵҐ૬ͷ‫ٯ‬ϑʔϦΤม‫׵‬Λߦ͍ɼಘΒΕͨ೾‫ʹܗ‬ର͠͞Βʹ࣌ؒྖҬͰඪ४ภ͕ࠩ τ Ͱ͋ΔΨ΢ε૭Λֻ͚߹Θ
ͤΔ͜ͱͰ wavelet ͕ಘΒΕΔɽཚ਺ͷֻ͚߹Θͤ͸ϑΟϧλΛࡶԻ‫ۦͰݯ‬ಈ͢Δ͜ͱͱ౳ՁͰ͋Γɼແ੠Ի෦෼Ͱ͸೾‫ܗ‬ͷඇप‫ظ‬ੑ͕ߴ͘ͳΔ͜ͱΛߟྀͨ͠߹੒ํ๏Ͱ͋Δɽ·ͨɼΨ΢ε૭ͷֻ͚߹Θͤ͸ɼप೾਺ಛੑΛอͪͭͭɼ߹੒ͨ͠ແ੠෦ͷ wavelet ͕̍ϑϨʔϜ௕ (64 ms) ʹ޿͕Δ͜ͱʹΑΓࣃ੾Εͷѱ͍Ի੠ʹͳΔ͜ͱΛ๷͙ޮՌ͕͋Δɽ͜ͷ wavelet Λ౳ִؒ Δt Ͱ഑ஔ͢Δ͜ͱʹΑΓແ੠Ի෦෼ͷ೾‫͕ܗ‬߹੒͞ΕΔɽຊ‫Ͱڀݚ‬͸ɼτ = 7.5 msɼΔt = 5.5 msͱͨ͠ɽ

日本音響学会講演論文集

3HMM ֶशͷͨΊͷ CWM ಛ௃ྔநग़

3.1ϑϨʔϜ୯Ґಛ௃ྔநग़ͷ໰୊఺ຊষͰ͸ɼCWM ෼ੳ߹੒‫ ͮ͘جʹܥ‬HMM Ի੠߹੒ͱɼͦͷͨΊͷಛ௃ྔநग़ͷվྑʹ͍ͭͯड़΂ΔɽલষͰड़΂ͨ CWM ಛ௃ྔͷநग़͸ɼϑϨʔϜ୯ҐͷॲཧͰ͋ͬͨɽҰํɼҰൠʹ GMM ͷύϥϝʔλਪఆ͸ཁૉ෼෍ͷॱংͷ೚ҙੑ͕ଘࡏ͢Δɽ͢ͳΘͪϑϨʔϜ୯ҐͰಠཱʹύϥϝʔλਪఆΛߦͬͨ৔߹ɼҟͳΔϑϨʔϜʹ͓͍ͯɼಉҰͷΠϯσοΫεk ͱཁૉ෼෍ͷҰ؏ੑ͕อূ͞Εͳ͍ɽHMM Ի੠߹੒Ͱ͸ෳ਺ͷϑϨʔϜ͔Β߹੒ͷͨΊͷԻ‫ڹ‬ϞσϧΛߏங͢ΔͨΊɼ͜ͷෆ੔߹ʹΑͬͯ඼࣭͕ྼԽ͢ΔՄೳੑ͕͋Δɽ

3.2

CWM ಛ௃ྔͷ࣌ؒભҠ֬཰Ϟσϧ

3.1 અͰड़΂ͨ໰୊Λղܾ͢ΔͨΊʹɼμk ͷ࣌ؒมಈʹ͍ͭͯ৽ͨʹ֬཰ϞσϧΛಋೖ͢Δ. μk ͷ࣌ؒมಈ͕ฏ‫ ۉ‬0 ͷਖ਼‫ن‬෼෍ʹै͏ͱԾఆ͢Δɽͭ·Γɼ(t)͋Δฏ‫ۉ‬஋ಛ௃ྔ͕࣌ࠁ t ʹͯ μk Ͱ͋Δͱ͖ɼ࣌
(t+1)

ࠁ t + 1 ʹͯ μk(t+1)

P (μk΁มԽ͢ΔભҠ֬཰Λɼ

(t)

(t+1)

|μk ) = N (μk(t); μk , νk2 )(4)ͱఆΊΔɽ͜͜Ͱɼ֤ΠϯσοΫε k ʹ͍ͭͯɼਖ਼
‫ن‬෼෍ͷ෼ࢄ νk2 ͸‫ڐ‬༰͞ΕΔ μk ͷ࣌ؒมಈͷఔ౓Λද͢ɽ͜ͷ৽ͨͳ֬཰Ϟσϧͷಋೖ͸ɼநग़͞ΕΔฏ‫ۉ‬஋ύϥϝʔλΛ࣌ؒํ޲ʹฏ‫׈‬Խ͠ɼ݁Ռͱ͠
ͯॱং͕ަ୅͢Δ֬཰Λ௿‫͢ݮ‬ΔޮՌΛ࣋ͭҰํͰɼભҠ֬཰ϞσϧͷಋೖʹΑΓɼۙࣅ GMM ͱɼ‫؍‬ଌεϖΫτϩάϥϜͱͷ‫૿͕ࠩޡ‬େ͢Δɽ

3.3

CWM ಛ௃ྔநग़ΞϧΰϦζϜͷվྑલड़ͷ࣌ؒભҠ֬཰ϞσϧΛಋೖͨ͠৔߹ɼCWMಛ௃ྔͷநग़͸‫؍‬ଌεϖΫτϩάϥϜͱϞσϧεϖΫτϩάϥϜͱͷҧ͍Λද͢ҎԼͷ໨తؔ਺ͷ࠷খԽʹΑ࣮ͬͯ‫͞ݱ‬ΕΔɽ

J(Y |F ) = I(Y |F ) +T −1K
1  (t+1)(t)(μ− μk )2 (5)2νk2 t=1 kk

ͨͩ͠ T ͸Ի੠͔ΒಘΒΕͨεϖΫτϧͷશϑϨʔϜ਺Ͱ͋Δ. [6] ͱಉ༷ʹɼJensen ͷෆ౳ࣜΛ༻͍ͯิॿؔ਺Λಋೖ͢Δɽ͜ͷͱ͖ɼμk Λআ͘ύϥϝʔλʹ͍ͭͯ͸ɼ2 ষͱಉ͡ߋ৽ࣜͰ͋ΔɽҰํ μk ʹ͍ͭͯ͸ɼ࣌ؒભҠ֬཰ϞσϧΛߟྀͨ͠ҎԼͷࣜʹ(1) (2)ΑΓߋ৽͞ΕΔɽ࣌‫ྻܥ‬ϕΫτϧΛ μk = (μk ɼμk(T )(t)ɼ· · · , μk )T ͱ͢Δͱɼ {μk } ͷߋ৽ࣜ͸ɼμ∗k =1(Dk + Ek )−1 Fk
2(6)ͱॻ͚Δɽͨͩ͠ɼ

- 288 -Dk=D(i,j)=1  (i,j) D(i, j ∈ [1, T ]) (7)2νk2i,j⎧1(i = j = {1, T })⎪⎪⎨2(i = j ∈ [2, T − 1])(8)−1(|i − j| = 1)⎪⎪⎩0(other)

2012年9月

4CWM ಛ௃ྔΛ༻͍ͨ HMM Ի੠߹੒

4.1

߹੒खॱ

CWM Λ෼ੳ߹੒‫͢ͱܥ‬Δ HMM Ի੠߹੒ͷखॱΛҎԼʹࣔ͢ɽ
1. ֶशʹ༻͍ΔԻ੠ʹ͍ͭͯɼSTRAIGHT ෼ੳʹΑͬͯɼ‫ج‬ຊप೾਺ͱεϖΫτϧแབྷΛநग़͠
ͨɽ3 ষͰड़΂ͨΞϧΰϦζϜʹΑΓεϖΫτϧ
แབྷ͔Β CWM ಛ௃ྔநग़Λߦͬͨɽ
2. ֤ϑϨʔϜຖͷ GMM ͷύϥϝʔλ (μk , σk , wk )ͱɼ͞Βʹͦͷ̍֊ɼ̎֊ͷ࣌ؒඍ෼ྔ Δ, Δ2 ,ΛซͤͯεϖΫτϧύϥϝʔλͱͯ͠ CWM ಛ௃ྔΛಘΔɽ͞ΒʹલͷεςοϓͰಘͨ‫ج‬ຊप೾਺ʹ͍ͭͯɼର਺‫ج‬ຊप೾਺ɼͦͷ 2 ֊·Ͱͷ࣌ؒඍ෼Λಛ௃ྔͱͯ͠࿈݁ͨ͠ɽ
3. લड़ͷಛ௃ྔΛ༻͍ͯɼHMM Ի੠߹੒ͷͨΊͷϞσϧֶशΛߦ͏ɽֶश͞ΕͨϞσϧΛ༻͍ͯɼධՁ༻ͷจষʹରͯ͠ରԠ͢Δ CWM ಛ௃ྔͱ‫ج‬ຊप೾਺ͷ‫ྻܥ‬Λੜ੒͢Δɽ
4. 2 ষͷ CWM Λ༻͍ͨ೾‫߹ܗ‬੒ΞϧΰϦζϜʹΑΓɼ࣮ࡍʹԻ੠Λ߹੒͢Δɽ

Fig. 2 Chain Λಋೖ͠ͳ͍৔߹ͷ {μk } நग़݁Ռʢࠞ
߹਺:10ʣɹಉҰ৭͔ͭಉҰγϯϘϧͷྻ͕̍ͭͷฏ‫ۉ‬஋ಛ௃ྔ μk ʹରԠ͢ΔɽପԁʹΑΓ‫ڧ‬ௐͨ͠Օॴ
ʹॱংͷೖΕସ͕͑֬ೝ͞ΕΔɽ

4.2

Fig. 3 Chain Λಋೖͨ͠৔߹ͷ {μk } நग़݁Ռ(ࠞ߹਺:10) ಉҰ৭͔ͭಉҰγϯϘϧͷྻ͕̍ͭͷฏ‫ۉ‬஋ಛ௃ྔ μk ʹରԠ͢Δɽ
Ek
(i,j)

Ek

Fk(i)

Fk

=

1  (i,j) Ek(i, j ∈ [1, T ])2σk2i,jω Y (ω, i)λk (ω, i)===01(i)(F )i (i ∈ [1, T ])σk2 k
ωY (ω, i)λk (ω, i)(9)(i = j)(10)(i = j)(11)(12)ωͰ͋Δɽͨͩ͠ɼλk ͸ิॿؔ਺๏ʹ͓͚Δิॿม਺Ͱ͋Δɽ࣌ؒભҠ֬཰ϞσϧΛಋೖ͠ͳ͍৔߹ͷಛ௃ྔநग़ͷ݁ՌΛ Fig. 2 ʹɼ࣌ؒભҠ֬཰ϞσϧΛಋೖͨ͠৔߹ͷ݁ՌΛ Fig. 3 ʹࣔͨ͠ɽ༻͍ͨԻ੠ɼGMMͷࠞ߹਺ɼॳ‫ظ‬஋ͷઃఆ͸ಉҰͰ͋Δɽνk ͷ஋ʹ͍ͭͯ͸ɼμk ͷ࣌ؒมԽͷඪ४ภ͕ࠩϝϧप೾਺্࣠Ͱ΄΅ҰఆͱͳΔΑ͏ఆΊͨɽμk ͷ࣌ؒมԽ͕ฏ‫׈‬Խ͞Εɼॱংͷަ୅͕‫ݮ‬গ͍ͯ͠Δͱ͕֬ೝͰ͖ΔɽԻ੠߹੒࣮‫ݧ‬

CWM ʹΑΔಛ௃ྔද‫ݱ‬Λ༻͍ͨ౷‫ܭ‬తԻ੠߹੒ͷԻ੠࠶‫ݱ‬ੑΛ֬ೝ͢ΔͨΊɼલड़ͷ߹੒खॱʹै͍ɼ࣮ࡍʹ HMM Ի੠߹੒Λߦͬͨɽֶशʹ͸ɼHTS 2.1
ͷσϞεΫϦϓτ [7] ʹಉࠝ͞Εͨஉੑ࿩ऀ 1 ໊ͷԻ੠ʢαϯϓϦϯάप೾਺ 16 kHz ɾαϯϓϧαΠζ 16bit ʣͷ͏ͪ 450 จΛ༻͍ɼධՁจষͱͯ͠ 53 จΛ༻͍ͨ1 ɽϑϨʔϜγϑτ 5ms Ͱ STRAIGHT ෼ੳΛߦ͍ɼεϖΫτϧแབྷ͓Αͼ‫ج‬ຊप೾਺Λநग़ͨ͠‫ ޙ‬K=10 ͱͯ͠ɼCWM ಛ௃ྔΛநग़ͨ͠ɽԻ‫ڹ‬Ϟ
σϧ͸ 5 ঢ়ଶ left-to-right ͷӅΕηϛϚϧίϑϞσϧͰ͋Γɼର਺‫ج‬ຊप೾਺ʹ͍ͭͯ͸ MSD-HMM ͱͨ͠ɽHMM ͷֶशʹ͸ HTS 2.1 Λ༻͍ͨ [8]ɽCWMʹ‫ͮ͘ج‬೾‫߹ܗ‬੒Ͱ͸ϑϨʔϜ௕ 64 msɼϑϨʔϜγϑτ 5 ms ͱͯ͠߹੒Λߦͬͨɽͳ͓ಛ௃ྔ‫ྻܥ‬ੜ੒ͷࡍɼ‫಺ྻܥ‬มಈʢGlobal Variance; GVʣΛߟྀ͠ͳ͍ύϥϝʔλੜ੒Λߦͬͨɽ
4.3

࣮‫݁ݧ‬Ռͱߟ࡯

࣮‫݁ݧ‬Ռͷྫͱͯ͠ɼATR ͷ J02 จʮట๮Ͱ΋ೖ͔ͬͨͱɼҰॠ๻͸ࢥͬͨʯʹ͍ͭͯɼαϯϓϧԻ੠ͱ߹੒Ի੠ͷεϖΫτϩάϥϜΛɼͦΕͧΕ Fig. 4(a)ɼ
Fig. 4(b) ʹͦΕͧΕࣔ͢ɽ·ͨɼઌ಄ͷԻૉ/o/ͷதԝ෇ۙͷϑϨʔϜʹ͍ͭͯɼ(1) αϯϓϧԻ੠ͷεϖΫτϧแབྷ (੨) (2) CWM ಛ௃ྔʹΑΓ߹੒ͨ͠Ի
੠ͷεϖΫτϧแབྷ (੺) (3) ैདྷ๏Ͱ߹੒ͨ͠Ի੠ͷεϖΫτϧแབྷ (ࠇ) Λ Fig. 5 ʹࣔ͢ɽͨͩ͠ɼैདྷ๏ͱ͸ɼ24 ࣍ͷϝϧέϓετϥϜʹΑΔख๏Ͱ͋Δ [3]ɽఏҊख๏ʹΑΔ߹੒Ի੠͸ɼεϖΫτϧแབྷɾεϖΫτϩάϥϜ͕͓͓ΉͶ࠶‫͞ݱ‬Ε͍ͯΔ͜ͱ͕֬ೝ͞Εͨɽௌ‫্ײ‬ɼಛʹ༗੠Իɾແ੠Ի͕ࠞͬͨ͟Ի੠ʹ͍ͭͯɼϝϧέϓετϥϜʹΑΔ߹੒Ի੠Ͱ͸ɼແ੠෦ͷΨ΢εࡶԻ‫ۦ‬ಈͷԻ੠͕‫ޙ‬ͷ༗੠෦ͷ
1 ൃ࿩಺༰͸ ATR Իૉόϥϯε෼Ͱ͋Γɼֶशσʔλ͕αϒηοτ A-IɼධՁจষ͕αϒηοτ J ʹରԠ͍ͯ͠Δɽ

日本音響学会講演論文集- 289 -2012年9月

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7LPH V(a) αϯϓϧԻ੠

Fig. 5)UHTXHQF\ N+]Իૉ/o/ͷε΃Ϋτϧแབྷ࠶‫݁ݱ‬Ռ)UHTXHQF\ N+]
7LPH V(b) ߹੒Ի੠Fig. 4 εϖΫτϩάϥϜ (ʮখ͞ͳә԰ʹ೤‫ؾ‬ͷ༷ͳ΋ͷ͕Έͳ͗Δʯ)Ի੠ʹӨ‫͠ڹ‬ɼࡶԻ͕ࠞͬͨ͟Α͏ͳԻʹͳΔ܏޲͕͕͋ͬͨɼఏҊख๏Ͱ͸͜ͷΑ͏ͳ܏޲͕վળ͞Εͨɽ͜Ε͸ɼFIR ‫ܕ‬ϑΟϧλΛ༻͍ͨޮՌͰ͋Δͱߟ͑ΒΕΔɽҰํͰɼఏҊ๏ʹΑΓ߹੒ͨ͠Ի੠͸ɼαϯϓϧԻ੠΍ϝϧέϓετϥϜʹΑΔ߹੒Ի੠ʹൺ΂ɼ͜΋ͬͨΑ͏ͳҹ৅Λ༩͑ΔԻ੠ʹͳͬͨɽओͳ‫ݪ‬Ҽ͸ɼFig. 5 ʹ֬ೝ͞ΕΔΑ͏ͳɼϑΥϧϚϯτͷฏ‫׈‬ԽͰ͋Δͱߟ͑ΒΕΔɽϑΥϧϚϯτ͕ฏ‫׈‬Խ͢Δ܏޲͸ɼଞͷ฼Իʹ͍ͭͯ΋ಉ༷ʹ֬ೝ͞Εͨɽ͜ͷ‫ݪ‬Ҽͱͯ͠͸ɼ• ཁૉ෼෍ͷରԠΛҰ؏ͤ͞ΔͨΊʹɼಛ௃ྔͷ࣌ؒભҠϞσϧͷΈͰ͸ෆे෼Ͱ͋Γɼಛ௃ྔ͕ฏ‫ۉ‬Խͨ͠• CWM ͷࠞ߹਺͕εϖΫτϧแབྷΛද‫͢ݱ‬ΔͨΊʹ͸ෆे෼Ͱ͋ͬͨ
• ಛ௃ྔͷ࣌ؒભҠϞσϧͷಋೖ͕ѱӨ‫ڹ‬Λ‫΅ٴ‬ͨ͠ͳͲ͕ߟ͑ΒΕɼ඼࣭޲্ͷͨΊʹ͸ɼwk ʹର͢Δ̜̫ͷಋೖ΍ɼಛ௃ྔநग़ख๏ʹ͍ͭͯվળͷ༨஍
͕͋Δɽ

5͓ΘΓʹຊ‫Ͱڀݚ‬͸ɼ८ճ‫ܕ‬ϑΟϧλͷ੍࣌ؒ‫ޚ‬ಛੑͷ໰୊Λղܾ͠ɼLSPɼέϓετϥϜͷ૒ํͷಛ௃ྔͷར఺

日本音響学会講演論文集

Λ౷߹͢ΔՄೳͳϞσϧͰ͋Δ CWM ෼ੳ߹੒‫ܥ‬Λར༻͠ɼ͜Εʹ‫ͮ͘ج‬ಛ௃ྔΛ༻͍ͨ HMM Ի੠߹੒Λ‫ݕ‬౼ͨ͠ɽఏҊ๏ʹΑΓ߹੒͞ΕͨԻ੠ͱɼ࣮ࡍʹಡΈ্͛ΒΕͨԻ੠ͷεϖΫτϩάϥϜ͸ྨࣅ͓ͯ͠ΓɼHMM Ի੠߹੒͕ՄೳͰ͋Δ͜ͱ͕֬ೝ͞Εͨɽಛʹ༗੠Իɾແ੠Ի͕ࠞͬͨ͟Ի੠ʹ͍ͭͯɼ‫ۦ‬ಈࡶԻͷӨ‫͕ڹ‬཈͑ΒΕɼFIR ϑΟϧλΛ༻͍ΔޮՌ͕‫ݱ‬Εͨͱߟ͑ΒΕΔɽҰํɼϑΥϧϚϯτ͕ฏ‫׈‬Խ͠ɼԻ੠͕͜΋Δ܏޲͕͋Γɼຊख๏ͷ߹੒Ի੠ͷ඼࣭ྼԽͷ‫ݪ‬Ҽͱͳ͍ͬͯΔͱߟ͑ΒΕΔɽಛ௃ྔநग़ख๏ͷߋͳΔվྑ΍ɼwk ʹର͢Δ GV ͷಋೖͳͲͷ޻෉Λߦ͏͜ͱͰɼߴ඼࣭ͳԻ੠߹੒͕ՄೳʹͳΔͱߟ͑ΒΕΔɽԻ੠ͷ඼࣭޲্ʹऔΓ૊Ήͱͱ΋ʹɼ߹੒Ի੠ͷओ‫؍‬ධՁ࣮‫ݧ‬Λߦ͍ैདྷ๏ͱൺֱ͢Δͳ
Ͳɼ඼࣭ʹର͢ΔఆྔධՁΛߦ͏༧ఆͰ͋Δɽࢀߟจ‫ݙ‬[1] ᒈ෢໵ଞɼ“ෳ߹΢ΣʔϒϨοτϞσϧʹΑΔԻ੠߹੒ͷ‫ݕ‬౼ɼ”೔ຊԻ‫ֶڹ‬ձ 2006 ೥य़‫ൃڀݚق‬දձߨԋ࿦จूɼ2-11-7ɼ2006ɽ
[2] ؅ଜঢଞɼ “ઢεϖΫτϧରʢLSPʣԻ੠෼ੳ߹
੒ํࣜʹΑΔԻ੠৘ใѹॖɼ”ిࢠ௨৴ֶձ࿦จࢽɼJ64-Aɼppɽ599-606ɼ1981ɽ
[3] ಙా‫ܙ‬Ұଞɼ “ಈతಛ௃ྔΛ༻͍ͨ HMM ͔ΒͷԻ੠ύϥϝʔλੜ੒ΞϧΰϦζϜɼ”೔ຊԻ‫ֶڹ‬
ձࢽɼvol.53ɼno.3ɼpp.192-200ɼ1997ɽ
[4] K. Hashimoto et al.ɼProc. Blizzard Challenge
Workshop 2011.
[5] Hideki Kawahara et al., “Restructuring speech
representations using a pitch-adaptive timefrequency smoothing and an instantaneousfrequency-based F0extractionɼ”Speech CommunicationɼVolɽ27ɼNoɽ3-4ɼppɽ187-207ɼ
1999ɽ
[6] ُԬ߂࿨ଞɼ“εϖΫτϧแབྷͱௐ೾ߏ଄ͷ߹੒ؔ਺ϞσϧʹΑΔԻ੠෼ੳɼ”೔ຊԻ‫ֶڹ‬ձ 2005೥ळ‫ൃڀݚق‬දձߨԋ࿦จूɼ2-6-4ɼ2005ɽ
[7] http://hts.sp.nitech.ac.jp/[8] શ ᖶՏଞɼ“HMM Ի੠߹੒γεςϜ (HTS) ͷ։ൃɼ”৘ใॲཧֶձ‫ڀݚ‬ใࠂɼSLP Ի੠‫ޠݴ‬৘ใॲཧ 2007 (129)ɼ301-306ɼ2007-12-20ɼ2007ɽ

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