6,329 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
Exploring the Encoding Layer and Loss Function in End-to-End Speaker and Language Recognition System
In this paper, we explore the encoding/pooling layer and loss function in the
end-to-end speaker and language recognition system. First, a unified and
interpretable end-to-end system for both speaker and language recognition is
developed. It accepts variable-length input and produces an utterance level
result. In the end-to-end system, the encoding layer plays a role in
aggregating the variable-length input sequence into an utterance level
representation. Besides the basic temporal average pooling, we introduce a
self-attentive pooling layer and a learnable dictionary encoding layer to get
the utterance level representation. In terms of loss function for open-set
speaker verification, to get more discriminative speaker embedding, center loss
and angular softmax loss is introduced in the end-to-end system. Experimental
results on Voxceleb and NIST LRE 07 datasets show that the performance of
end-to-end learning system could be significantly improved by the proposed
encoding layer and loss function.Comment: Accepted for Speaker Odyssey 201
Seeing voices and hearing voices: learning discriminative embeddings using cross-modal self-supervision
The goal of this work is to train discriminative cross-modal embeddings
without access to manually annotated data. Recent advances in self-supervised
learning have shown that effective representations can be learnt from natural
cross-modal synchrony. We build on earlier work to train embeddings that are
more discriminative for uni-modal downstream tasks. To this end, we propose a
novel training strategy that not only optimises metrics across modalities, but
also enforces intra-class feature separation within each of the modalities. The
effectiveness of the method is demonstrated on two downstream tasks: lip
reading using the features trained on audio-visual synchronisation, and speaker
recognition using the features trained for cross-modal biometric matching. The
proposed method outperforms state-of-the-art self-supervised baselines by a
signficant margin.Comment: Under submission as a conference pape
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