Speaker Verification (SV) systems involve mainly two individual stages:
feature extraction and classification. In this paper, we explore these two
modules with the aim of improving the performance of a speaker verification
system under noisy conditions. On the one hand, the choice of the most
appropriate acoustic features is a crucial factor for performing robust speaker
verification. The acoustic parameters used in the proposed system are: Mel
Frequency Cepstral Coefficients (MFCC), their first and second derivatives
(Deltas and Delta- Deltas), Bark Frequency Cepstral Coefficients (BFCC),
Perceptual Linear Predictive (PLP), and Relative Spectral Transform -
Perceptual Linear Predictive (RASTA-PLP). In this paper, a complete comparison
of different combinations of the previous features is discussed. On the other
hand, the major weakness of a conventional Support Vector Machine (SVM)
classifier is the use of generic traditional kernel functions to compute the
distances among data points. However, the kernel function of an SVM has great
influence on its performance. In this work, we propose the combination of two
SVM-based classifiers with different kernel functions: Linear kernel and
Gaussian Radial Basis Function (RBF) kernel with a Logistic Regression (LR)
classifier. The combination is carried out by means of a parallel structure
approach, in which different voting rules to take the final decision are
considered. Results show that significant improvement in the performance of the
SV system is achieved by using the combined features with the combined
classifiers either with clean speech or in the presence of noise. Finally, to
enhance the system more in noisy environments, the inclusion of the multiband
noise removal technique as a preprocessing stage is proposed.

提出了结合不同声学特征和支持向量机分类器的方法，以改善噪声环境下说话人验证系统的性能。结果表明，在干净语音或噪声存在的情况下，使用组合特征和组合分类器可以显著提高系统性能。最后，提出了多频带噪声去除技术作为预处理阶段，用以增强在嘈杂环境下的系统。