12,366 research outputs found
Robust Speech Detection for Noisy Environments
This paper presents a robust voice activity detector (VAD) based on hidden Markov models (HMM) to improve speech recognition systems in stationary and non-stationary noise environments: inside motor vehicles (like cars or planes) or inside buildings close to high traffic places (like in a control tower for air traffic control (ATC)). In these environments, there is a high stationary noise level caused by vehicle motors and additionally, there could be people speaking at certain distance from the main speaker producing non-stationary noise. The VAD presented in this paper is characterized by a new front-end and a noise level adaptation process that increases significantly the VAD robustness for different signal to noise ratios (SNRs). The feature vector used by the VAD includes the most relevant Mel Frequency Cepstral Coefficients (MFCC), normalized log energy and delta log energy. The proposed VAD has been evaluated and compared to other well-known VADs using three databases containing different noise conditions: speech in clean environments (SNRs mayor que 20 dB), speech recorded in stationary noise environments (inside or close to motor vehicles), and finally, speech in non stationary environments (including noise from bars, television and far-field speakers). In the three cases, the detection error obtained with the proposed VAD is the lowest for all SNRs compared to AceroÂżs VAD (reference of this work) and other well-known VADs like AMR, AURORA or G729 annex b
Discriminative Features via Generalized Eigenvectors
Representing examples in a way that is compatible with the underlying
classifier can greatly enhance the performance of a learning system. In this
paper we investigate scalable techniques for inducing discriminative features
by taking advantage of simple second order structure in the data. We focus on
multiclass classification and show that features extracted from the generalized
eigenvectors of the class conditional second moments lead to classifiers with
excellent empirical performance. Moreover, these features have attractive
theoretical properties, such as inducing representations that are invariant to
linear transformations of the input. We evaluate classifiers built from these
features on three different tasks, obtaining state of the art results
Factorization of Discriminatively Trained i-vector Extractor for Speaker Recognition
In this work, we continue in our research on i-vector extractor for speaker
verification (SV) and we optimize its architecture for fast and effective
discriminative training. We were motivated by computational and memory
requirements caused by the large number of parameters of the original
generative i-vector model. Our aim is to preserve the power of the original
generative model, and at the same time focus the model towards extraction of
speaker-related information. We show that it is possible to represent a
standard generative i-vector extractor by a model with significantly less
parameters and obtain similar performance on SV tasks. We can further refine
this compact model by discriminative training and obtain i-vectors that lead to
better performance on various SV benchmarks representing different acoustic
domains.Comment: Submitted to Interspeech 2019, Graz, Austria. arXiv admin note:
substantial text overlap with arXiv:1810.1318
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