In 1986, led by Prof. Zuoying Wang,
several departments of Tsinghua University, including Department of Radio
Electronics(renamed to Department of Electronic
Engineering in 1987), Department of Automation,
Department of Precision Instruments, Department of
Foreign Language, etc., jointly applied for and
undertook the project "Computer Natural Language
Translation" belonging to
the first batch projects of
"863" Program of China, which consisted of three sub-projects:
speech recognition, machine translation and speech synthesis.
This project carried out in 1987. Prof. Wang was
responsible for the overall project coordination and
research on the sub-project "Computer Speech Recognition". Meanwhile, Prof. Wang organized research
team and established speech recognition technology laboratory(SRTL)
of Department of Electronic Engineering Tsinghua University.
After the establishment of SRTL, substantial pioneering work
was carried out on Chinese speech recognition.
In May of Year 1987, Professor Wang proposed Duration Distribution Based Hidden Markov Model(DDBHMM),
which was able to describe the real distribution of
speech units instead of imposing exponential
distribution of segment length on speech units according
to the classic Hidden Markov Model(HMM). Different from the classic HMM, there was post-effectiveness using DDBHMM.
Subsequently Professor Wang proposed training algorithm and recognition algorithm for DDBHMM, succeeding in the establishment
of the DDBHMM overall solution and forming a more comprehensive speech recognition theory framework.
SRTL was not only a pioneer
on speech recognition research, but also a frontier in
industrial system design and development. In 1988, SRTL was the first to achieve
speaker-dependent whole-syllable Chinese isolated-word
recognition system based on Dynamic Time Warping(DTW). In 1992, isolated Chinese character speech recognition system, THED919 Dictation Machine,
jointly developed by SRTL and China National Electronic
Devices Corp., passed the identification of Ministry of Electronic.
In addition to the steady research sponsorship from national "863"
Program, the project also brought a powerful
stimulation to the entire speech recognition industry in China. Chinese speech recognition technology
had been rapidly developing with the hardwork
of numerous domestic research institution and researcher, including SRTL. In year 1994,1995 and 1998, "863" intelligent computer system experts continuously organized
evaluation of speech recognition technology for three times, the content of which extended from speaker-dependent
isolated-word recognition to continuous speech
recognition and finally reached speaker-independent continuous speech
recognition. SRTL won three consecutive champions, establishing the domestic leading position on speech recognition technology.
In order to convert advanced technology into real-life products, based on the continuous speech recognition system
for the evaluation of "863" program in 1998, SRTL launched THEESP system in 1999, the first domestic online real-time Chinese continuous speech
recognition system with full independent intellectual property rights. Speech Processing Department of Koninklijke Philips N.V. ever
purchased the right to use the system and took advantage of it to develop the Chinese version of the continuous speech recognition product
From year 2002, considering the
application prospect of speech recognition technology,
SRTL strated R&D on IVR(Interactive Voice
Response) platform oriented multi-channel concurrent speech
recognition engine and limitative resources oriented
embedded speech recognition engine. During the same
year, Beijing Tianlang-tech Co., Ltd. was initiated by Tsinghua University and Beijing High Technology
Venture Capital Co., Ltd., to promote the industrial development of speech recognition technology. In Year 2003, Tianlang
launched the first domestic telephone speech recognition
engine supporting multi-channel concurrence. In the same year, "VoiceCards", an embedded
speech recognition product for Symbian platform, won the prize for excellence of Individual Efficiency Class of Nokia-Symbian S60 Application
Contest. Although Tianlang almost stopped operation in 2004 due to various reasons, as one domestic pioneer in industrialization of
speech recognition technology, it has made the contribution to the development of speech recognition industry.
In 2006, Tsinghua-iFlyTek Joint Laboratory
for Speech Technologies was founded for the strategic alliance with the domestic leading enterprise on speech
industry, Anhui USTC iFLYTEK Co., Ltd. While persisting in
the research on multi-platform
and multi-application oriented speech recognition technology, SRTL began to enter the field of speech search technology. Later, SRTL undertook
the project "Exploration Research on Content-based High
Performance Speech Search Technology" belonging to
the "863" Program of the Eleventh Five-Year Plan
for National Economic and Social Development, and had successively completed technology prototypes and demo systems for navigation-oriented speech
search system for massive place-names(Voice Search for POI), massive speech documents oriented content retrieval system(Spoken Term Detection,
audio matching and filtering system, etc.
Along with the extension of research interests and contents,
the lab formally renamed to "Multimedia Signal and Intelligent
Information Processing Laboratory"(MSIIP) in 2009. Aimed at contents implied in multimedia signal, MSIIP has been carrying out
the research on the cognition, understanding, efficient
management and utilization of data and information,
adopting massive data oriented processing technologies including
statistical pattern recognition, machine learning,
data mining, etc.