TAP CHI KHOA HQC - DAI HOC DONG NAI, SO 04

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TAP CHI KHOA HQC - DAI HOC DONG NAI, SO 04 - 2017 ISSN 2354-1482 NHAN D A N G TIENG NOI CHtT SO VIET AF D U N G

T R O N G H E THONG NHAP D I E M

TkS. Thdi Duy Quf TOM TAT

Nkdn dgng tiing ndi cua con nguai dd vd dang thu hut su quan tdm nghien cuu cua nhieu nhd khoa hgc khi md cong nghi ty dgng hda ngdy cdng cd nhiiu img diing tiong thuc tien cudc sdng. Ngkiin cuu nhdn dgng tieng ndi Viet cdng duac quan tdm nghiin cuu nhieu tiong nhirng ndm gdn day, tuy vgy cho din nay cdc kit qud vdn chua thda mdn nhirng bdi todn ddt ra tu thuc te cugc song do tinh chdt phuc tgp vi ngie dm cua tiing Viet. Bdi bdo trinh bdy bdi todn tim ddc trung, hudn luyin vd nhgn dgng tiing ndi Viet, irng dung tiong hi thdng nhgp diim. Cdc kit qud duac kiem nghiim bdng cdc tieng noi sd r&i rgc vd td hgp ngdn, dong th&i tich hgp tiong chuang trinh nhgp diem cho he thdng hiin hdnh.

Tir kkoa: Nhgn dgng tiing ndi Viet, nhgn dgng chir sd, speech recognition, HMM.MFCC

1. Dft van de l.I. Gi&i tkieu

Trong giao tifip gifta ngudi vdi ngudi, tifing ndi la phuang phap trao ddi thdng tin ty nMen va hifiu qud nhat. Myc tifiu cda cdc ky thudt nhdn dgng tifing ndi theo nghia rpng la tgo ra nhiing mdy cd kha nang nhdn bifit dugc thdng tin tifing ndi vd hdnh ddng theo tieng ndi dd. Nhdn dgng tieng ndi la mdt phdn cua qua trinh tim kifira thdng tin de raay cd thfi "nghe",

"hieu" vd "hdnh dpng" theo thdng rin ddng thdi "ndi lgi" dfi hodn tdt vigc trao ddi thdng tin.

Cho dfin nay, van dfi giao tifip gifta con ngudi vd raay tinh my dd dupc cdi thien nhifiu nhung chu yeu van cdn kha thu cdng thdng qua cdc tMfit bi nhdp, xuat. Giao tifip vdi tMet bi raay bang tifing ndi se la phuang thdc giao tifip van

minh vd ty nMfin nhat. Ddu an giao tifip ngudi - may se raat di raa diay vdo do la cam nhan cua sy giao tifip gifta ngudi vdi ngudi, nfiu hodn tMfin tM ddy se Id mfit phuang thuc giao tiep tien Igi vd Meu qua trong cdng viec [4]. Mac dii nhan dang ngdn ngft tifing Anh da dupc ngMfin cdu kha hodn tMfin nhung do cd sy khdc biet ve ngu dm, ngu ngMa vdi tieng Viet nfin khd cd thfi dp dyng cdc chuong trinh nhdn dgng khdc Men hdnh dfi nhgn dgng tieng Viet. Mdt he thdng nhan dgng tifing ndi d nudc ta phdi dugc xdy dyng tren nen tang ciia tifing ndi tifing Viet [5].

1.2. Tong quan ^nk kink nghien ciru Cdc icy thudt nhdn dang tieng ndi tren thfi gidi da cd td thdp nifin 60 vd da dat dupc nhieu thanh tyu ddng kfi [I].

Cac he thdng nhdn dang gigng ndi tifing Anh da dugc dp dyng tt-ong nMfiu ITnh Tmong D?i hpc Da Lat

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TAP CHi KHOA HQC - DAI HQC DONG NAI, SO 04 - 2017 ISSN 2354-1482 vyc nhu tt-ong xd ly van bdn bdng tifing

ndi, ty dgng hda ttong phdn xudng, cdc he thdng an ninh, dich thudt, he thdng tt:a Idi ty ddng, robot thdng ramh,...

Tgi Vigt Nam, do cdn tuy thuge vdo dieu kien nghien cdu vd sy phdc tgp ciia ngft dm tifing Viet nfin cdc nghien cdu vfi hg thfing nhgn dang gigng ndi tifing Vigt vdn cdn nhieu hgn che va dfin nay chua cd he thdng ndo hoan chinh [4].

Mac du vdy, hifin nay cung cd nhifiu cdng trinh ngMen cdu cua cac nhd khoa hgc, cd thfi kfi den PGS. TS. Luang Chi Mai (Vifin Cdng nghfi Thdng tin Ha Ndi), PGS.TS. Vu Hdi Quan (Dai hgc Khoa hgc Ty nhifin TP. Hd Chi Minh)... mang Igi nhieu nhftng thdnh cdng trfin Iy thuyet va dng dyng. Trong nhiing san phdm ndi bat, cd thanh tyu cua sdn phdm VSpeech ciia nhdm BK02 [9], tuang tac gigng ndi vdi chu vifit dfi difiu kien mdt sd chdc ndng ca bdn tren may tinh. Mgt sd sdn pham cua cac cdng ty ciing da tich hgp cac chdc nang tim dudng di, cdy xdng, ATM,... trfin cac hg thdng di ddng.

Mac du cd nhifiu nghifin crai va san phdm dng dung thyc tfi nhung trong cdc san phdm vfi nhgn dang tifing ndi van chua cd sdn phdm nao dap ung cho cdng vific nhap difim, mdt cdng vific thudng xuyfin trong nha trudng.

1.3. Muc tieu cua di tdi Dfi tdi nghien cdu thd nghifim hudng nhdn dgng tifing ndi Viet dya trfin vific trich ddc trung cua tieng ndi bdng phuong phap MFCC (Mel Frequency Ceptrums Coefficients), va nhdn dgng bdng md hinh HMM (Hidden Markov Models). Dong thdi mdt chuang ttinh nhgn dang bdng tifing ndi Viet dupc xay dyng vdi bd tu vyng nhd la cdc tifing ndi sd, dung trong he thdng nhgp diem. Chuong trinh dugc xdy dung bang ngdn ngft C# trfin nfin .Net dua vdo mdt sd thu vign. Cac budc minh hga sd dung mdt sd ham trong ngdn ngft Matlab.

2. Hf thong nhan dang tilng noi Mfit Vfi mat tdng quat, radt he thdng nhgn dgng thudng bao gdm hai phdn chinh la hudn luyin (training) va nhdn dgng (recognition) dupc thfi Men nhu trong hinh I. Trong dd ''Rut tiich dgc tnmg" la qua trinh dua ra dugc nhftng dac tnmg thich hpp cho nhan dang.

"Hudn luy4n" Id qua trinh he thdng

"hgc" va "Iuu trft" nhung mdu chudn dugc cung cap, tu dd hinh thanh bg td vyng cua he thdng. Va qua trinh "nhgn dgng" Id quyfit dinh xem mdu nao dugc dua vao can cu vdo bp tu vyng da dupc huan luyfin.

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TAP CHI KHOA HQC - DAI HQC DONG NAI, S6 04 - 2017 ISSN 2354-1482

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Hinh 1: Tdng quan mdt hi thong nhdn dgng Mdt hfi thdng nhdn dang tieng ndi

Cling theo quy tac cdc budc cua mdt h§

nhan dang tdng quat. Tin hieu thu vdo la cac dm thanh ndi td micro, dgc trung cua dm thanh thudng la tifing vd dra vi ciia ngdn ngu vd qud trinh hudn luyen dya trfin cac tap tm am thanh da thu vao td trudc.

3. Tien xir Iy

Tifing ndi sau khi dupc thu td micro se dugc lay mau tin hifiu, mdt raau tin hieu thudng dugc bifiu difin dudi dgng sdng. Hinh 2 md td sdng ara cua cdc sd tu radt dfin mudi. Ddi vdi tin Meu dm thanh, mdu se dugc Idy theo mdt chu ky thdi gian, cdng thdc lay mdu dupc xdc dinh bdi cdng thuc 1:

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Hinh 2: Md hinh sdng dm cdc sd tic mgt den mu&i Tin hifiu sau khi ldy xong se thdng

qua mdt bd lgc tin hifiu. Bd Igc tin hifiu cd the bao gdra bd khd nhifiu, bO khdi phyc tin hifiu bien dang, bd dd tim difim cudi dfi xdc dinh ddu la tifing

dn, ddu la tifing ndi vd khoang lang gifta hai tifing ndi. Mdt vi du vfi phuong phap dd tim difim cufii dugc m d t d t r o n g M n h 3 .

146

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l A P C H i K H O A H O C - D A I H O C D O N G NAI, SO 04 - 2017 ISSN 2354-1482 L^ niii dtt?c xit ly

Hinh 3: Mdt vi du ve dd tim diim cudi Pong sdng dm

>j Lam 10 tinhiyg|—»j IhanJdamg | Ujin) I L ^ eu'a sS I

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\ Hian ttch d^c tning |

Moik mqt vector dfc trung

Hinh 4: Cdc quy trinh trong rut trich dgc tnmg MFCC 4. Rut trich dac trung Phdn ttich ddc trung se dua ra dugc Sau qud trinh tifin xd ly da cd vector dac trung cho md hinh cdn nhan dupc cac mdu tifing ndi khd nhifiu. dang. Cd nhifiu phuong phap trich dgc

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TAP CHJ KHQA HOC - BAI HQC B 6 N G NAI, SO 04 - 2017 ISSN 2354-1482 trung khac nhau nhu Wavelets, LPC,

MFCC... Chung tdi chpn phuong phdp trich dac tinng MFCC (Thang tdn sd Mel) do tdc do tinh todn cao, dg tin cay Idn vd dd dupc su dyng rat hifiu qua ttong cdc chuong trinh nhdn dgng tifing ndi tren thfi gidi [4].

Phuong phdp rut trich dgc tnmg MFCC dupc md td nhu trong hinh 4.

Trong md hinh nay ta cd bdn budc de nit trich dgc tnmg nhu: Idra rd tin

hieu, phdn khung, lay cda sd vd phdn tich ddc tnmg. Chi tifit cdc budc dugc trinh bay theo cdc muc sau day.

4.1. Ldm ro tin hieu

Budc ndy rayc dich chinh la Iam tang tin hieu va ndi rd cdc ddc trung Clia tin hieu giup nang cao mdc do nhay cdm trong cdc budc sau [3].

Bd ldm rd tin hieu cd phuong trinh sai phan nhu sau:

s =^ 5 ( M ) — as(^n — 1) (2) Original wave. s(n)

-<•** f H M ^{^}

. l ^ y -

After pre-emphasis: s_(n)=s(nj-a's(n-1), a=0.950000

Hinh 5. Mo hinh bu&c sdng tru&c vd sau khi ldm ro tin hieu 4.2. Pkdn kkung

Trong budc ndy, s dugc chia thanh cdc khung, mdi khung gdm N mdu, khoang cdch giua cac khung la M mdu. Hinh 5 minh hga each phan

x^{n) = s{M .i-\-n) ^

thdnh cdc khung vdi M= '^ N. Nfiu ta ky hieu khung thd i la x,(n) va cd tdt cd L khung trong tin higu tifing ndi thi:

=0,l,...,N-l;i=0,I,...,L-l (3)

148

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TAPCHi KHOA HOC - BAI HOC aONO NAI, SO 04 - 2017 ISSN 2354-1482

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r\ 1 ^r\ ^\j

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^{^\} ^\ ^M

Hinh 6: Am tiing ndi dugc phdn dogn thdnh cdc khung 4.3. Ldy cwa so

Budc tiep theo trong xu Iy la lay cda sd tm hifiu dng vdi mdi khung dfi gidm thifiu gidn doan tin hieu d ddu vd cudi mdi khung. Day tin hieu con dupc ldy ra td radt tin hifiu dai hon hodc ddi vd hgn x(n) ggi Id mdt cda sd

tin hifiu. Qud trinh quan sat tin hifiu x(n) bang mdt doan x(N(n)) trong khoang no... (no + N - 1) tuong duong vdi vific nhdn x(n) vdi mdt hdm cua sd w(n-no) nhu sau:

lg nhgn dang tieng ndi, ) thudng hay dupc dung araing, cd dang nhu cdng

x^{n) = x{n).w{n-n^) = Y^

(4) Trong nhgn dang tieng ndi,

hdm cda sd thudng hay dupc dung nhat Id Hamraing, cd dang nhu cdng

thdc (5). Tin hieu cua cda sd Hamming dugc bieu dien trong hinh 7.

|n|£JV/2

\n\>Nn (5) 0.54+0.46cos(2s-n/iV)

6enef3lized Hunmoig Wiitdm): (1«Hi-eosCZ»>'|X'1)). 0£ndJ-t

Hinh 7: Md hinh song cica so Hamming

4.4. Trich ckgn dgc tiwng bien ddi Furier ngugc dya ti-fin do ldn Budc cudi cung trong trich chgn logarit cua ngo ra cua bg Igc.

dac trung MFCC bao gora thyc hifin

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TAP CHI KHOA HOC - DAI HOC BONG NAI, SO 04 - 2017 ISSN 2354-1482

•nlHlitti •\i\\ I iiiiiiHliii »4}*»-

*] B i ^ dSi Conn | Bien d^i sang miln tin so

4^ijWjyyY\ I ^^ ^ ^^ ^^ *>5 **?*=

I Logo I I Bifin dfii Fourier

tam giac tren ^lang Mel

Moi khung m$t vector d§c tnrng

Hinh 8: Cdc bu&c trich chgn ddc trung MFCC

Sau khi tin Mfiu tifing ndi dugc theo [4], chiing tdi dinh nghia mdt ttich dac tnmg thi radi td dupc dac vector dgc tnmg bao gdra 10 thdnh trung bdi mdt ma trgn he sd thyc. Dya phan nhu sau:

yt = [fu frft+h ere^ax, d /max, fmin. fmax-fsl, fmin-fed, fmirrfsU fmax-fedJ 0) trong do:

-f, la tdn sd ca ban tai khung tin hieu t -f,+i la tdn sd ca bdn tgi khung tin hifiu t+1 - e, Id nang Iupng tgi khung tm hieu t

- Smax la nang lugng eye dgi trong phdn huu thanh (khdng phai nhieu) - (i la sd khung phan huu thanh

-fmax la tan sd ca ban eye dgi trong vung hftu thanh -fmm la tan sd co bdn eye tieu trong viing huu thanh -fl la tan sd co ban d khung dau tifin trong vung hftu thanh -fed la tan sd co ban d khung cudi cung trong vung hftu thanh

Do md hinh HMM rdi rac dupc dng Sau khi thyc hifin xong phdn nit dung dfi nhdn dgng nfin nhftng vector trich dgc trung, ket qua Id cd m0t co sd ddc tnmg ndy phdi dupc udc Iugng

vector thdnh rapt chi sd codebook rdi rac. Phuong phap dugc su dung dfi udc lugng vector la phuong phap K-means.

5. Huan luyen cho mo hinh

du lifiu cdc vector dgc trung tuang ung vdi timg tu. Phan hudn luyfin su dung rad hinh Markov dn vdi dft lifiu huan luyfin Id cdc vector dgc hning cd dupc td phdn trudc. U'ng vdi mdi tu cdn nhdn dang thi mdt co sd dft lieu cac ddc trung

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TAP CHi KHQA HQC - BAI HQC DONG NAI, SO 04 - 2017 ISSN 2354-1482 tu cac ldn dgc khdc nhau. Sau dd se udc

lupng cdc thdng sd cua rad hinh X =' (A, B. ic) dfi xdc sudt P(0\X) dat eye dai, tuong ung vdi mdi td la mdt X xac dinh.

Dfi nhgn dgng mdt tu thi chi vigc tinh xac suat chudi quan sdt ciia td dd ung vdi cac X, da dugc huan Iuyen va chgn mau nao cd xdc sudt Idn nhdt.

6. Thuc nghifm hfi thong nhdp diem dira vdo tieng ndi

Dfi thd nghiem he thdng nhan dgng, chung tdi su dung bd cdng cy Sphinx [7]. Ddy la bd cdng cy raa ngudn rad, tich hgp cd chdc ndng hudn luyfin va nhdn dang tren hai md hinh Id ngdn ngft Bang 1: Mdt so tie vyng,

va rad hinh ngft dm. Bd cdng cy ndy cung tien hanh nhdn dang tifing ndi dya theo cdc budc nhu da neu d trfin.

Bd dft li^u dung cho nhdn dang vd hudn luyen la cac tap tin dgng .wav, dugc thu dm tu 100 ngudi. Do ung cyng cua chiing tdi la nhdn dgng dya h-fin chu sd nfin chi xay dyng md hinh td vyng vdi cdc chft sd nhu: khdng, mgt, hai, ba, bdn, ndm, sdu. bdy, tdm, chin, muai, phay, len, xudng.

Md Mnh ngdn ngft dugc su dyng bang ma VIQR mmh hga nhu tt-ong bdng I:

chic so dimg trong hudn luyen M6 hinh tix

vmig KHO'NG M<yr HAI BA BO^'N NA(M SA'U BA?Y

Y nghia IChong Mot Hai Ba Bon Nam Sau Bay

Ky t\r can nhan dang

0 1 2 3 4 5 6 7

M6 hinh tir virng TA'M CHFN MU+O+'I PHA"?Y LE^N XU0"'NO VA(NG THI

Y nghia Tam Chin Miroi Phay LSn Xuong V5ng thi

K^ ty cin nhSn dang

8 9 10

Up Down

VT

Ket qua thu nghiera dupc thfi hien nhdn dgng dung (86%), cd 3 chft sd bj ttong bang 2. Bdng nay cho thdy kfit nhdn dgng nham ldn, trung binh kfit qua nhdn dang: Cd 12/15 chii sd dupc qud nhdn dgng Id 93.3%.

Bdng 2: Kit qud thyc nghiem So

0 1 2 3

Ket qua nhSn dang 100%

70%

100%

50%

8 9 10 Phay

100%

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TAP c m KHOA HOC - BAI HQC BONG NAI. SO 04-2017 ISSN 2354-1482 4

5 6 7

100%

80%

100%

Len Xuong Ving thi

100%

Trung binh: 9 3 J %

Bang 3 md ta ket qua nhdm ldn ciia cac cap chft sd: Aip/ - mu&i, ba - bd}\ sdu - bdn.

Bang 3: Muc do nkdm ldn ngir dm cua mdt so tic vung Tir

vung Mot Ba Sau

Tff b) nhan d^ng Dham Muoi Bay Bon

T i l l 30%

50%

20%

Trong img dung nhdp difim, chiing tfii xay dyng chuong trinh dya trfin mdt sd bg thu \ien nhu Sphinx [7], VSpeech.dll [9] va System.speech [10].

Du lifiu dua vao la cac sd tu I den 9 va cdc yeu cdu nhu phdy, Ifin, xudng, vdng tM. De thudn tien cho vific nhgn dang cac diem le, chiing tdi cung dua vao cac

bd sd Ie nhu: mdt phay mdt, mdt phay hai... Chuang trinh dupc \iet bang ngdn ngft C= n-fin nfin .Net (Mnh 9), ket qua nhdp diera vdi do chinh xac 93.3"o.

Do du [igu huan Iuyen cdn it, kM nhdn dang, chung tdi cung diifit l i ^ thera thfira nhftng ggi y dfi ndng cao mite dp nbgn dang cho he thdng nhap difim.

O

1

4 Speech Bangnil ^

- - - . 1 j

Katuc , 73 1 1-2 1

1

Hinh 9: Chirang trinh nhdp diim bdng gigng noi 1. Ket luan

Md hinh thu nghiem nhdn dang tifing ndi chu sd trong tifing Viet theo hudng kei hgp MFCC vd HMM tuy cdn nMfiu ban che nhung da dap ung dupc myc tieu cua de tdi. Chuang trinh thu ngMfim dupc su dung de nhgp cac he thdng difim le vdi bd tu vyng nhd

cho do chinh xac cd the chap nhan dupc (trfin 90%). Nfiu difiu kien cho phep, nhdm tac gid se tdi im hda chuang trinh nhgn dang, dua them nhifiu bg dft hgu hudn luyfin dfi dgt dugc kfit qud cao hem \ a tang tdc dp xuly.

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TAP CHi KHOA HOC - DAI HQC BONG NAI, SO 04 - 2017 ISSN 2354-1482 TAI LIEU THAM KHAO

1. Thai Hung Van, Dd Xuan Dgt, V5 Van Tudn, (2003), Nghien cim cdc ddc trung cua tiing Viet dp dung vdo nhgn dgng tiing ndi tiing Viet (Luan vdn Dai hgc), Dgi hgc Khoa hpc Ty nhien TP. Hd Chi Minh

2. Nguyfin Van Gidp, Trdn Viet Hung (2006), Ky thugt nhdn dgng tiing ndi img dyng trong diiu khien

3. Nguyen Hdng Quang (2004), Nhgn dgng tiing ndi Viet, tim hiiu vd ieng dung, Trudng Dai hgc Khoa hgc Ty nhien

4. http://bk02.sourceforge.net/vspeechsdk/vietnaraese/

5. Phan Nguyfin Phuc Quoc, Ha Thuc Phung (2009), Hi thong nhdn dgng tiing ndi (Ludn vdn Dgi hgc), Dai hgc Bach khoa TP. Hd Chi Minh

6. CMUSphinx Wiki: http://cmusphinx.sourceforge.net/wiki/

7. http://rasdn.microsoft.com

8. Cao Xuan Hgo (1998), Tiing Viet - mdy vdn di ngie dm, ngir phdp, ngir nghia, Nhd xuat bdn Gido dye

9. Xuedong Huang, Alex Acero, Hsiao-wuen Hon (2001), Spoken language Processing, Camegie Mellon University

10. Mikael Nilson, Marcus Ejnarson (2002), Speech recognition using Hidden Markov Model performance evaluation in noisy enviroment, ebook

SPEECH RECOGNITION VIETNAMESE IN APPLYING TO INPUTTING SCORES

ABSTRACT

Speech recognition of the human voice has attracted the attention of many scientists while automation technology has been more and more applied to real life.

Researching Vietnamese speech recognitions has also been concerned in recent years, but so far the results have not yet satisfied the problems posed by real life complex because ofthe nature of phonological Vietnamese. This paper presents the problem of finding features, training and applying Vietnamese speech recognition to inputting score. The results are tested by the discrete and short voice digital while the application was built for the current system.

Keywords: Speech recognition, HMM, MFCC

TAP CHI KHOA HQC - DAI HOC DONG NAI, SO 04

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