Bayesian learning for hidden Markov model with Gaussian mixture state observation densities
نویسندگان
چکیده
An investigation into the use of Bayesian learning of the parameters of a multivariate Gaussian mixture density has been carried out. In a framework of continuous density hidden Markov model (CDHMM), Bayesian learning serves as a uni ed approach for parameter smoothing, speaker adaptation, speaker clustering and corrective training. The goal is to enhance model robustness in a CDHMM-based speech recognition system so as to improve performance. Our approach is to use Bayesian learning to incorporate prior knowledge into the training process in the form of prior densities of the HMM parameters. The theoretical basis for this procedure is presented and results applying it to parameter smoothing, speaker adaptation, speaker clustering, and corrective training are given. Zusammenfassung. Wir berichten uber eine Untersuchung zum Einsatz der Bayes'schen Lerntheorie zur Schaetzung der Parameter von multi-variaten Gauss'schen Verteilungsdichten. Im Rahmen eines \Hidden Markov Modells" mit kontinuierlicher Dichteverteilungen (CDHMM) stellt die Bayes'sche Theorie einen einheitlichen Ansatz dar zur Parameterglaettung, Sprecheradaption, Sprecherklusterung und zum korrigierenden Training. Das Ziel ist, die Modellrobustheit eines auf CDHMM basierenden Spracherkennungssystems in Hinblick auf die Ergebnisse zu verbessern. Unser Ansatz ist, Bayes'sches Lernen zu benutzen, um Vorwissen in Form von initialen Dichten der HMM-Parameter in den Trainingsprozess einzubringen. Wir stellen die theoretische Basis f ur dieses Verfahren dar und wenden es zur Glaettung von Parametern, Sprecheradaption, Sprecherklusterung und im korrigierenden Training an. R esum e. Une etude sur l'utilisation de l'apprentissage bay esien des param etres de densit ees multigaussiennes a et e e ectu ee. Dans le cadre des mod eles markoviens cach es a densities d'observations continues (CDHMM), l'apprentissage bay esien est un outil tr es g en eral applicable au lissage des param etres, a l'adaptation au locuteur, a l'estimation de mod eles par groupe de locuteurs et a l'apprentissage correctif. Le but est d'augmenter la robustesse des mod eles d'un syst eme de reconnaissance a n d'en am eliorer les performances. Notre approche consiste a utiliser l'apprentissage bay esien pour incorporer une connaissance a priori dans le processus d'apprentissage sous forme de densit es de probabilit es des param etres des modeles markoviens. La base th eorique de cette proc edure est pr esent ee, ainsi que les r esultats obtenus pour le lissage des param etres, l'adaptation au locuteur, l'estimation de mod eles 3 propres a chaque sexe, et l'apprentissage correctif. 4
منابع مشابه
Maximum a posteriori estimation for multivariate Gaussian mixture observations of Markov chains
In this paper a framework for maximum a posteriori (MAP) estimation of hidden Markov models (HMM) is presented. Three key issues of MAP estimation, namely the choice of prior distribution family, the specification of the parameters of prior densities and the evaluation of the MAP estimates, are addressed. Using HMMs with Gaussian mixture state observation densities as an example, it is assumed ...
متن کاملOn-Line Adaptive Learning of the Continuous Density Hidden Markov Model Based on Approximate Recursi - Speech and Audio Processing, IEEE Transactions on
We present a framework of quasi-Bayes (QB) learning of the parameters of the continuous density hidden Markov model (CDHMM) with Gaussian mixture state observation densities. The QB formulation is based on the theory of recursive Bayesian inference. The QB algorithm is designed to incrementally update the hyperparameters of the approximate posterior distribution and the CDHMM parameters simulta...
متن کاملOn-line adaptive learning of the continuous density hidden Markov model based on approximate recursive Bayes estimate
We present a framework of quasi-Bayes (QB) learning of the parameters of the continuous density hidden Markov model (CDHMM) with Gaussian mixture state observation densities. The QB formulation is based on the theory of recursive Bayesian inference. The QB algorithm is designed to incrementally update the hyperparameters of the approximate posterior distribution and the CDHMM parameters simulta...
متن کاملHidden Markov Model for Speech Recognition
In this paper, a theoretical framework for Bayesian adaptive training of the parameters of discrete hidden Markov model (DHMM) and of semi-continuous HMM (SCHMM) with Gaussian mixture state observation densities is presented. In addition to formulating the forward-backward MAP (maximum a posterion’) and the segmental MAP algorithms for estimating the above HMM parameters, a computationally effi...
متن کاملBayesian Learning of Gaussian Mixture Densities for Hidden Markov Models
An investigation into the use of Bayesian learning of the parameters of a multivariate Gaassian mixture density has been carried out. In a continuous density hidden Markov model (CDHMM) framework, Bayesian learning serves as a unified approach for parameter smoothing, speaker adaptation, speaker clustering, and corrective training. The goal of this study is to enhance model robustness in a CDHM...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Speech Communication
دوره 11 شماره
صفحات -
تاریخ انتشار 1991