In this study, we propose to investigate triplet loss for the purpose of an alternative feature representation for ASR. We consider a general non-semantic speech representation, which is trained with a self-supervised criteria based on triplet loss called TRILL, for acoustic modeling to represent the acoustic characteristics of each audio. This strategy is then applied to the CHiME-4 corpus and CRSS-UTDallas Fearless Steps Corpus, with emphasis on the 100-hour challenge corpus which consists of 5 selected NASA Apollo-11 channels. An analysis of the extracted embeddings provides the foundation needed to characterize training utterances into distinct groups based on acoustic distinguishing properties. Moreover, we also demonstrate that triplet-loss based embedding performs better than i-Vector in acoustic modeling, confirming that the triplet loss is more effective than a speaker feature. With additional techniques such as pronunciation and silence probability modeling, plus multi-style training, we achieve a +5.42% and +3.18% relative WER improvement for the development and evaluation sets of the Fearless Steps Corpus. To explore generalization, we further test the same technique on the 1 channel track of CHiME-4 and observe a +11.90% relative WER improvement for real test data.
more »
« less
FeaRLESS: Feature Refinement Loss for Ensembling Self-Supervised Learning Features in Robust End-to-end Speech Recognition
Self-supervised learning representations (SSLR) have resulted in robust features for downstream tasks in many fields. Recently, several SSLRs have shown promising results on automatic speech recognition (ASR) benchmark corpora. However, previous studies have only shown performance for solitary SSLRs as an input feature for ASR models. In this study, we propose to investigate the effectiveness of diverse SSLR combinations using various fusion methods within end-to-end (E2E) ASR models. In addition, we will show there are correlations between these extracted SSLRs. As such, we further propose a feature refinement loss for decorrelation to efficiently combine the set of input features. For evaluation, we show that the proposed “FeaRLESS learning features” perform better than systems without the proposed feature refinement loss for both the WSJ and Fearless Steps Challenge (FSC) corpora.
more »
« less
- Award ID(s):
- 2016725
- PAR ID:
- 10402503
- Date Published:
- Journal Name:
- ISCA INTERSPEECH-2022
- Page Range / eLocation ID:
- 3058 to 3062
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
ISCA (Ed.)In this paper, we present MixRep, a simple and effective data augmentation strategy based on mixup for low-resource ASR. MixRep interpolates the feature dimensions of hidden representations in the neural network that can be applied to both the acoustic feature input and the output of each layer, which generalizes the previous MixSpeech method. Further, we propose to combine the mixup with a regularization along the time axis of the input, which is shown as complementary. We apply MixRep to a Conformer encoder of an E2E LAS architecture trained with a joint CTC loss. We experiment on the WSJ dataset and subsets of the SWB dataset, covering reading and telephony conversational speech. Experimental results show that MixRep consistently outperforms other regularization methods for low-resource ASR. Compared to a strong SpecAugment baseline, MixRep achieves a +6.5% and a +6.7% relative WER reduction on the eval92 set and the Callhome part of the eval'2000 set.more » « less
-
null (Ed.)“Transcription bottlenecks”, created by a shortage of effective human transcribers are one of the main challenges to endangered language (EL) documentation. Automatic speech recognition (ASR) has been suggested as a tool to overcome such bottlenecks. Following this suggestion, we investigated the effectiveness for EL documentation of end-to-end ASR, which unlike Hidden Markov Model ASR systems, eschews linguistic resources but is instead more dependent on large-data settings. We open source a Yoloxochitl Mixtec EL corpus. First, we review our method in building an end-to-end ASR system in a way that would be reproducible by the ASR community. We then propose a novice transcription correction task and demonstrate how ASR systems and novice transcribers can work together to improve EL documentation. We believe this combinatory methodology would mitigate the transcription bottleneck and transcriber shortage that hinders EL documentation.more » « less
-
null (Ed.)This paper describes three open access Yoloxóchitl Mixtec corpora and presents the results and implications of end-to-end automatic speech recognition for endangered language documentation. Two issues are addressed. First, the advantage for ASR accuracy of targeting informational (BPE) units in addition to, or in substitution of, linguistic units (word, morpheme, morae) and then using ROVER for system combination. BPE units consistently outperform linguistic units although the best results are obtained by system combination of different BPE targets. Second, a case is made that for endangered language documentation, ASR contributions should be evaluated according to extrinsic criteria (e.g., positive impact on downstream tasks) and not simply intrinsic metrics (e.g., CER and WER). The extrinsic metric chosen is the level of reduction in the human effort needed to produce high-quality transcriptions for permanent archiving.more » « less
-
Jean-Jacques Rousseau; Bill Kapralos; Henrik I. Christensen; Michael Jenkin; Cheng-Lin (Ed.)Exponential growth in the use of smart speakers (SS) for the automation of homes, offices, and vehicles has brought a revolution of convenience to our lives. However, these SSs are susceptible to a variety of spoofing attacks, known/seen and unknown/unseen, created using cutting-edge AI generative algorithms. The realistic nature of these powerful attacks is capable of deceiving the automatic speaker verification (ASV) engines of these SSs, resulting in a huge potential for fraud using these devices. This vulnerability highlights the need for the development of effective countermeasures capable of the reliable detection of known and unknown spoofing attacks. This paper presents a novel end-to-end deep learning model, AEXANet, to effectively detect multiple types of physical- and logical-access attacks, both known and unknown. The proposed countermeasure has the ability to learn low-level cues by analyzing raw audio, utilizes a dense convolutional network for the propagation of diversified raw waveform features, and strengthens feature propagation. This system employs a maximum feature map activation function, which improves the performance against unseen spoofing attacks while making the model more efficient, enabling the model to be used for real-time applications. An extensive evaluation of our model was performed on the ASVspoof 2019 PA and LA datasets, along with TTS and VC samples, separately containing both seen and unseen attacks. Moreover, cross corpora evaluation using the ASVspoof 2019 and ASVspoof 2015 datasets was also performed. Experimental results show the reliability of our method for voice spoofing detection.more » « less