Speaker segmentation and clustering

This survey focuses on two challenging speech processing topics, namely: speaker segmentation and speaker clustering. Speaker segmentation aims at finding speaker change points in an audio stream, whereas speaker clustering aims at grouping speech segments based on speaker characteristics. Model-based, metric-based, and hybrid speaker segmentation algorithms are reviewed. Concerning speaker clustering, deterministic and probabilistic algorithms are examined. A comparative assessment of the reviewed algorithms is undertaken, the algorithm advantages and disadvantages are indicated, insight to the algorithms is offered, and deductions as well as recommendations are given. Rich transcription and movie analysis are candidate applications that benefit from combined speaker segmentation and clustering. © 2007 Elsevier B.V. All rights reserved

Speaker recognition for door opening systems

Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do ParanáBesides being an important communication tool, the voice can also serve for identification purposes since it has an individual signature for each person. Speaker recognition technologies can use this signature as an authentication method to access environments. This work explores the development and testing of machine and deep learning models, specifically the GMM, the VGG-M, and ResNet50 models, for speaker recognition access control to build a system to grant access to CeDRI’s laboratory. The deep learning models were evaluated based on their performance in recognizing speakers from audio samples, emphasizing the Equal Error Rate metric to determine their effectiveness. The models were trained and tested initially in public datasets with 1251 to 6112 speakers and then fine-tuned on private datasets with 32 speakers of CeDri’s laboratory. In this study, we compared the performance of ResNet50, VGGM, and GMM models for speaker verification. After conducting experiments on our private datasets, we found that the ResNet50 model outperformed the other models. It achieved the lowest Equal Error Rate (EER) of 0.7% on the Framed Silence Removed dataset. On the same dataset,« the VGGM model achieved an EER of 5%, and the GMM model achieved an EER of 2.13%. Our best model’s performance was unable to achieve the current state-of-the-art of 2.87% in the VoxCeleb 1 verification dataset. However, our best implementation using ResNet50 achieved an EER of 5.96% while being trained on only a tiny portion of the data than it usually is. So, this result indicates that our model is robust and efficient and provides a significant improvement margin. This thesis provides insights into the capabilities of these models in a real-world application, aiming to deploy the system on a platform for practical use in laboratory access authorization. The results of this study contribute to the field of biometric security by demonstrating the potential of speaker recognition systems in controlled environments.Além de ser uma importante ferramenta de comunicação, a voz também pode servir para fins de identificação, pois possui uma assinatura individual para cada pessoa. As tecnologias de reconhecimento de voz podem usar essa assinatura como um método de autenticação para acessar ambientes. Este trabalho explora o desenvolvimento e teste de modelos de aprendizado de máquina e aprendizado profundo, especificamente os modelos GMM, VGG-M e ResNet50, para controle de acesso de reconhecimento de voz com o objetivo de construir um sistema para conceder acesso ao laboratório do CeDRI. Os modelos de aprendizado profundo foram avaliados com base em seu desempenho no reconhecimento de falantes a partir de amostras de áudio, enfatizando a métrica de Taxa de Erro Igual para determinar sua eficácia. Osmodelos foram inicialmente treinados e testados em conjuntos de dados públicos com 1251 a 6112 falantes e, em seguida, ajustados em conjuntos de dados privados com 32 falantes do laboratório do CeDri. Neste estudo, comparamos o desempenho dos modelos ResNet50, VGGM e GMM para verificação de falantes. Após realizar experimentos em nossos conjuntos de dados privados, descobrimos que o modelo ResNet50 superou os outros modelos. Ele alcançou a menor Taxa de Erro Igual (EER) de 0,7% no conjunto de dados Framed Silence Removed. No mesmo conjunto de dados, o modelo VGGM alcançou uma EER de 5% e o modelo GMM alcançou uma EER de 2,13%. O desempenho do nosso melhor modelo não conseguiu atingir o estado da arte atual de 2,87% no conjunto de dados de verificação VoxCeleb 1. No entanto, nossa melhor implementação usando o ResNet50 alcançou uma EER de 5,96%, mesmo sendo treinado em apenas uma pequena parte dos dados que normalmente são utilizados. Assim, este resultado indica que nosso modelo é robusto e eficiente e oferece uma margem significativa de melhoria. Esta tese oferece insights sobre as capacidades desses modelos em uma aplicação do mundo real, visando implantar o sistema em uma plataforma para uso prático na autorização de acesso ao laboratório. Os resultados deste estudo contribuem para o campo da segurança biométrica ao demonstrar o potencial dos sistemas de reconhecimento de voz em ambientes controlados

Deep learning backend for single and multisession i-vector speaker recognition

The lack of labeled background data makes a big performance gap between cosine and Probabilistic Linear Discriminant Analysis (PLDA) scoring baseline techniques for i-vectors in speaker recognition. Although there are some unsupervised clustering techniques to estimate the labels, they cannot accurately predict the true labels and they also assume that there are several samples from the same speaker in the background data that could not be true in reality. In this paper, the authors make use of Deep Learning (DL) to fill this performance gap given unlabeled background data. To this goal, the authors have proposed an impostor selection algorithm and a universal model adaptation process in a hybrid system based on deep belief networks and deep neural networks to discriminatively model each target speaker. In order to have more insight into the behavior of DL techniques in both single- and multisession speaker enrollment tasks, some experiments have been carried out in this paper in both scenarios. Experiments on National Institute of Standards and Technology 2014 i-vector challenge show that 46% of this performance gap, in terms of minimum of the decision cost function, is filled by the proposed DL-based system. Furthermore, the score combination of the proposed DL-based system and PLDA with estimated labels covers 79% of this gap.Peer ReviewedPostprint (published version

VOICE BIOMETRICS UNDER MISMATCHED NOISE CONDITIONS

This thesis describes research into effective voice biometrics (speaker recognition) under mismatched noise conditions. Over the last two decades, this class of biometrics has been the subject of considerable research due to its various applications in such areas as telephone banking, remote access control and surveillance. One of the main challenges associated with the deployment of voice biometrics in practice is that of undesired variations in speech characteristics caused by environmental noise. Such variations can in turn lead to a mismatch between the corresponding test and reference material from the same speaker. This is found to adversely affect the performance of speaker recognition in terms of accuracy. To address the above problem, a novel approach is introduced and investigated. The proposed method is based on minimising the noise mismatch between reference speaker models and the given test utterance, and involves a new form of Test-Normalisation (T-Norm) for further enhancing matching scores under the aforementioned adverse operating conditions. Through experimental investigations, based on the two main classes of speaker recognition (i.e. verification/ open-set identification), it is shown that the proposed approach can significantly improve the performance accuracy under mismatched noise conditions. In order to further improve the recognition accuracy in severe mismatch conditions, an approach to enhancing the above stated method is proposed. This, which involves providing a closer adjustment of the reference speaker models to the noise condition in the test utterance, is shown to considerably increase the accuracy in extreme cases of noisy test data. Moreover, to tackle the computational burden associated with the use of the enhanced approach with open-set identification, an efficient algorithm for its realisation in this context is introduced and evaluated. The thesis presents a detailed description of the research undertaken, describes the experimental investigations and provides a thorough analysis of the outcomes

Iterative Unsupervised GMM Training for Speaker Indexing

The paper addresses a novel algorithm for speaker searching and indexation based on unsupervised GMM training. The proposed method doesn\'t require a predefined set of generic background models, and the GMM speaker models are trained only from test samples. The constrain of the method is that the number of the speakers has to be known in advance. The results of initial experiments show that the proposed training method enables to create precise GMM speaker models from only a small amount of training data