61,131 research outputs found
A non-linear VAD for noisy environments
This paper deals with non-linear transformations for improving the
performance of an entropy-based voice activity detector (VAD). The idea to use
a non-linear transformation has already been applied in the field of speech
linear prediction, or linear predictive coding (LPC), based on source separation
techniques, where a score function is added to classical equations in order to
take into account the true distribution of the signal. We explore the possibility
of estimating the entropy of frames after calculating its score function, instead
of using original frames. We observe that if the signal is clean, the estimated
entropy is essentially the same; if the signal is noisy, however, the frames
transformed using the score function may give entropy that is different in
voiced frames as compared to nonvoiced ones. Experimental evidence is given
to show that this fact enables voice activity detection under high noise, where
the simple entropy method fails
Exploring convolutional, recurrent, and hybrid deep neural networks for speech and music detection in a large audio dataset
Audio signals represent a wide diversity of acoustic events, from background environmental noise to spoken
communication. Machine learning models such as neural networks have already been proposed for audio signal
modeling, where recurrent structures can take advantage of temporal dependencies. This work aims to study the
implementation of several neural network-based systems for speech and music event detection over a collection of
77,937 10-second audio segments (216 h), selected from the Google AudioSet dataset. These segments belong to
YouTube videos and have been represented as mel-spectrograms. We propose and compare two approaches. The
first one is the training of two different neural networks, one for speech detection and another for music detection.
The second approach consists on training a single neural network to tackle both tasks at the same time. The studied
architectures include fully connected, convolutional and LSTM (long short-term memory) recurrent networks.
Comparative results are provided in terms of classification performance and model complexity. We would like to
highlight the performance of convolutional architectures, specially in combination with an LSTM stage. The hybrid
convolutional-LSTM models achieve the best overall results (85% accuracy) in the three proposed tasks. Furthermore,
a distractor analysis of the results has been carried out in order to identify which events in the ontology are the most
harmful for the performance of the models, showing some difficult scenarios for the detection of music and speechThis work has been supported by project âDSSL: Redes Profundas y Modelos
de Subespacios para Deteccion y Seguimiento de Locutor, Idioma y
Enfermedades Degenerativas a partir de la Vozâ (TEC2015-68172-C2-1-P),
funded by the Ministry of Economy and Competitivity of Spain and FEDE
End-to-end Audiovisual Speech Activity Detection with Bimodal Recurrent Neural Models
Speech activity detection (SAD) plays an important role in current speech
processing systems, including automatic speech recognition (ASR). SAD is
particularly difficult in environments with acoustic noise. A practical
solution is to incorporate visual information, increasing the robustness of the
SAD approach. An audiovisual system has the advantage of being robust to
different speech modes (e.g., whisper speech) or background noise. Recent
advances in audiovisual speech processing using deep learning have opened
opportunities to capture in a principled way the temporal relationships between
acoustic and visual features. This study explores this idea proposing a
\emph{bimodal recurrent neural network} (BRNN) framework for SAD. The approach
models the temporal dynamic of the sequential audiovisual data, improving the
accuracy and robustness of the proposed SAD system. Instead of estimating
hand-crafted features, the study investigates an end-to-end training approach,
where acoustic and visual features are directly learned from the raw data
during training. The experimental evaluation considers a large audiovisual
corpus with over 60.8 hours of recordings, collected from 105 speakers. The
results demonstrate that the proposed framework leads to absolute improvements
up to 1.2% under practical scenarios over a VAD baseline using only audio
implemented with deep neural network (DNN). The proposed approach achieves
92.7% F1-score when it is evaluated using the sensors from a portable tablet
under noisy acoustic environment, which is only 1.0% lower than the performance
obtained under ideal conditions (e.g., clean speech obtained with a high
definition camera and a close-talking microphone).Comment: Submitted to Speech Communicatio
Two-Dimensional Convolutional Recurrent Neural Networks for Speech Activity Detection
Speech Activity Detection (SAD) plays an important role in mobile communications and automatic speech recognition (ASR). Developing efficient SAD systems for real-world applications is a challenging task due to the presence of noise. We propose a new approach to SAD where we treat it as a two-dimensional multilabel image classification problem. To classify the audio segments, we compute their Short-time Fourier Transform spectrograms and classify them with a Convolutional Recurrent Neural Network (CRNN), traditionally used in image recognition. Our CRNN uses a sigmoid activation function, max-pooling in the frequency domain, and a convolutional operation as a moving average filter to remove misclassified spikes. On the development set of Task 1 of the 2019 Fearless Steps Challenge, our system achieved a decision cost function (DCF) of 2.89%, a 66.4% improvement over the baseline. Moreover, it achieved a DCF score of 3.318% on the evaluation dataset of the challenge, ranking first among all submissions
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