Gopal Ananthakrishnan

Learn More
We propose a unified framework to recover articulation from audiovisual speech. The nonlinear audiovisual-to-articulatory mapping is modeled by means of a switching linear dynamical system. Switching is governed by a state sequence determined via a Hidden Markov Model alignment process. Mel Frequency Cepstral Coefficients are extracted from audio while(More)
Subtle temporal and spectral differences between categorical realizations of para-linguistic phenomena (e.g., affective vocal expressions) are hard to capture and describe. In this paper we present a signal representation based on Time Varying Constant-Q Cepstral Coefficients (TVCQCC) derived for this purpose. A method which utilizes the special properties(More)
This paper explores the possibility and extent of non-uniqueness in the acoustic-to-articulatory inversion of speech, from a statistical point of view. It proposes a technique to estimate the non-uniqueness, based on finding peaks in the conditional probability function of the articulatory space. The paper corroborates the existence of non-uniqueness in a(More)
In order to study inter-speaker variability, this work aims to assess the generalization capabilities of data-based multi-speaker articulatory models. We use various three-mode factor analysis techniques to model the variations of midsagittal vocal tract contours obtained from MRI images for three French speakers articulating 73 vowels and consonants.(More)
This correspondence describes a method for automated segmentation of speech. The method proposed in this paper uses a specially designed filter-bank called Bach filter-bank which makes use of 'music' related perception criteria. The speech signal is treated as continuously time varying signal as against a short time stationary model. A comparative study has(More)
Julián Andrés Valdés Vargas, Pierre Badin, G. Ananthakrishnan, Laurent Lamalle (1) GIPSA-lab (Département Parole & Cognition), UMR 5216 CNRS – Grenoble University (2) Centre for Speech Technology, KTH (Royal Institute of Technology), Stockholm, Sweden (3) SFR1 RMN Biomédicale et Neurosciences (Unité IRM Recherche 3 Tesla), INSERM, CHU de Grenoble(More)
This paper studies the hypothesis that the acoustic-toarticulatory mapping is non-unique, statistically. The distributions of the acoustic and articulatory spaces are obtained by fitting the data into a Gaussian Mixture Model. The kurtosis is used to measure the non-Gaussianity of the distributions and the Bhattacharya distance is used to find the(More)
This paper discusses a model which conceptually demonstrates how infants could learn the normalization between infant-adult acoustics. The model proposes that the mapping can be inferred from the topological correspondences between the adult and infant acoustic spaces, that are clustered separately in an unsupervised manner. The model requires feedback from(More)
This paper introduces a general approach for binary classification of audiovisual data. The intended application is mispronunciation detection for specific phonemic errors, using very sparse training data. The system uses a Support Vector Machine (SVM) classifier with features obtained from a Time Varying Discrete Cosine Transform (TV-DCT) on the audio(More)