3,380 research outputs found
Max-margin Metric Learning for Speaker Recognition
Probabilistic linear discriminant analysis (PLDA) is a popular normalization
approach for the i-vector model, and has delivered state-of-the-art performance
in speaker recognition. A potential problem of the PLDA model, however, is that
it essentially assumes Gaussian distributions over speaker vectors, which is
not always true in practice. Additionally, the objective function is not
directly related to the goal of the task, e.g., discriminating true speakers
and imposters. In this paper, we propose a max-margin metric learning approach
to solve the problems. It learns a linear transform with a criterion that the
margin between target and imposter trials are maximized. Experiments conducted
on the SRE08 core test show that compared to PLDA, the new approach can obtain
comparable or even better performance, though the scoring is simply a cosine
computation
Full-info Training for Deep Speaker Feature Learning
In recent studies, it has shown that speaker patterns can be learned from
very short speech segments (e.g., 0.3 seconds) by a carefully designed
convolutional & time-delay deep neural network (CT-DNN) model. By enforcing the
model to discriminate the speakers in the training data, frame-level speaker
features can be derived from the last hidden layer. In spite of its good
performance, a potential problem of the present model is that it involves a
parametric classifier, i.e., the last affine layer, which may consume some
discriminative knowledge, thus leading to `information leak' for the feature
learning. This paper presents a full-info training approach that discards the
parametric classifier and enforces all the discriminative knowledge learned by
the feature net. Our experiments on the Fisher database demonstrate that this
new training scheme can produce more coherent features, leading to consistent
and notable performance improvement on the speaker verification task.Comment: Accepted by ICASSP 201
From features to speaker vectors by means of restricted Boltzmann machine adaptation
Restricted Boltzmann Machines (RBMs) have shown success in different stages of speaker recognition systems. In this paper, we propose a novel framework to produce a vector-based representation for each speaker, which will be referred to as RBM-vector. This new approach maps the speaker spectral features to a single fixed-dimensional vector carrying speaker-specific information. In this work, a global model, referred to as Universal RBM (URBM), is trained taking advantage of RBM unsupervised learning capabilities. Then, this URBM is adapted
to the data of each speaker in the development, enrolment and
evaluation datasets. The network connection weights of the adapted RBMs are further concatenated and subject to a whitening with dimension reduction stage to build the speaker vectors. The evaluation is performed on the core test condition of the NIST SRE 2006 database, and it is shown that RBM-vectors achieve 15% relative improvement in terms of EER compared to i-vectors using cosine scoring. The score fusion with i-vector attains more than 24% relative improvement. The interest of this result for score fusion yields on the fact that both vectors are produced in an unsupervised fashion and can be used instead of i-vector/PLDA approach, when no data label is available. Results obtained for RBM-vector/PLDA framework is comparable with the ones from i-vector/PLDA. Their score fusion achieves 14% relative improvement compared to i-vector/PLDA.Peer ReviewedPostprint (published version
- …