语音的视频录制包含相关的音频和视觉信息，为语音表示从扬声器的唇部运动和产生的声音提供了强大的信号。我们介绍了视听隐藏单元BERT（AV-HUBERT），是视听语音的自我监督的代表学习框架，这些屏幕屏蔽了多流视频输入并预测自动发现和迭代地精制多模式隐藏单元。 AV-HUBERT学习强大的视听语音表示，这些语音表示受益于唇读和自动语音识别。在最大的公众唇读基准LRS3（433小时）中，AV-Hubert达到32.5％WER，只有30个小时的标签数据，优于前一种最先进的方法（33.6％）培训，达到了一千次转录的视频数据（31k小时）。当使用来自LRS3的所有433小时的标记数据并结合自培训时，唇读WER进一步降低至26.9％。使用我们在相同的基准测试中使用您的视听表示，用于音频语音识别的相对效率为40％，而最先进的性能（1.3％Vs 2.3％）。我们的代码和模型可在https://github.com/facebookResearch/av_hubert获得

尽管视听模型与仅限音频模型相比可以产生卓越的性能和鲁棒性，但由于缺乏标记和未标记的视听数据以及每种方式部署一个模型的成本，它们的开发和采用受到阻碍。在本文中，我们提出了U-Hubert，这是一个自制的预训练框架，可以通过统一的蒙版群集预测目标来利用多模式和单峰语音。通过在预训练期间利用模态辍学，我们证明了一个微调模型可以在PAR上取得比较的性能或比最先进的模态特异性模型更好。此外，我们仅在音频上进行微调的模型可以通过视听和视觉语音输入来表现良好，从而实现了零击的模态概括，以实现语音识别和扬声器验证。特别是，我们的单个模型在带有音频/视听/视觉输入的LRS3上产生1.2％/1.4％/27.2％的语音识别单词错误率。

基于音频的自动语音识别（ASR）在嘈杂的环境中显着降低，并且特别容易受到干扰语音的影响，因为模型无法确定要转录的扬声器。视听语音识别（AVSR）系统通过将音频流与不变噪声不变的可视信息补充，帮助模型对所需扬声器的视觉信息来提高鲁棒性。但是，以前的AVSR工作仅关注监督学习设置;因此，通过可用的标记数据量阻碍了进度。在这项工作中，我们提出了一个自我监督的AVSR框架，建立在视听休伯特（AV-HUBERT），是最先进的视听语音表示学习模型。在最大可用的AVSR基准数据集LRS3中，我们的方法在存在的情况下使用少于10％的标签数据（433HR与30HR）之前的最先进（28.0％与14.1％）优于〜50％（28.0％vs.14.1％）禁止噪声，平均减少了基于音频模型的WER以上超过75％（25.8％与5.8％）。

We present RAVEn, a self-supervised multi-modal approach to jointly learn visual and auditory speech representations. Our pre-training objective involves encoding masked inputs, and then predicting contextualised targets generated by slowly-evolving momentum encoders. Driven by the inherent differences between video and audio, our design is asymmetric w.r.t. the two modalities' pretext tasks: Whereas the auditory stream predicts both the visual and auditory targets, the visual one predicts only the auditory targets. We observe strong results in low- and high-resource labelled data settings when fine-tuning the visual and auditory encoders resulting from a single pre-training stage, in which the encoders are jointly trained. Notably, RAVEn surpasses all self-supervised methods on visual speech recognition (VSR) on LRS3, and combining RAVEn with self-training using only 30 hours of labelled data even outperforms a recent semi-supervised method trained on 90,000 hours of non-public data. At the same time, we achieve state-of-the-art results in the LRS3 low-resource setting for auditory speech recognition (as well as for VSR). Our findings point to the viability of learning powerful speech representations entirely from raw video and audio, i.e., without relying on handcrafted features. Code and models will be made public.

本文调查了视听扬声器表示的自我监督的预训练，其中显示了视觉流，显示说话者的口腔区域与语音一起用作输入。我们的研究重点是视听隐藏单元BERT（AV-HUBERT）方法，该方法是最近开发的通用音频语音训练前训练框架。我们进行了广泛的实验，以探测预训练和视觉方式的有效性。实验结果表明，AV-Hubert可以很好地概括与说话者相关的下游任务，从而使标签效率提高了大约10倍的仅10倍，仅音频和视听扬声器验证。我们还表明，结合视觉信息，甚至仅仅是唇部区域，都大大提高了性能和噪声稳健性，在清洁条件下将EER降低了38％，在嘈杂的条件下将EER降低了75％。

Self-supervised approaches for speech representation learning are challenged by three unique problems: (1) there are multiple sound units in each input utterance, (2) there is no lexicon of input sound units during the pre-training phase, and (3) sound units have variable lengths with no explicit segmentation. To deal with these three problems, we propose the Hidden-Unit BERT (HuBERT) approach for self-supervised speech representation learning, which utilizes an offline clustering step to provide aligned target labels for a BERT-like prediction loss. A key ingredient of our approach is applying the prediction loss over the masked regions only, which forces the model to learn a combined acoustic and language model over the continuous inputs. HuBERT relies primarily on the consistency of the unsupervised clustering step rather than the intrinsic quality of the assigned cluster labels. Starting with a simple k-means teacher of 100 clusters, and using two iterations of clustering, the HuBERT model either matches or improves upon the state-ofthe-art wav2vec 2.0 performance on the Librispeech (960h) and Libri-light (60,000h) benchmarks with 10min, 1h, 10h, 100h, and 960h fine-tuning subsets. Using a 1B parameter model, HuBERT shows up to 19% and 13% relative WER reduction on the more challenging dev-other and test-other evaluation subsets. 1

Prior works on improving speech quality with visual input typically study each type of auditory distortion separately (e.g., separation, inpainting, video-to-speech) and present tailored algorithms. This paper proposes to unify these subjects and study Generalized Speech Enhancement, where the goal is not to reconstruct the exact reference clean signal, but to focus on improving certain aspects of speech. In particular, this paper concerns intelligibility, quality, and video synchronization. We cast the problem as audio-visual speech resynthesis, which is composed of two steps: pseudo audio-visual speech recognition (P-AVSR) and pseudo text-to-speech synthesis (P-TTS). P-AVSR and P-TTS are connected by discrete units derived from a self-supervised speech model. Moreover, we utilize self-supervised audio-visual speech model to initialize P-AVSR. The proposed model is coined ReVISE. ReVISE is the first high-quality model for in-the-wild video-to-speech synthesis and achieves superior performance on all LRS3 audio-visual enhancement tasks with a single model. To demonstrates its applicability in the real world, ReVISE is also evaluated on EasyCom, an audio-visual benchmark collected under challenging acoustic conditions with only 1.6 hours of training data. Similarly, ReVISE greatly suppresses noise and improves quality. Project page: https://wnhsu.github.io/ReVISE.

这项工作的目的是通过利用视频中的音频和视觉流的自然共同发生来研究语音重建（视频到音频）对语音重建（视频到音频）的影响。我们提出了Lipsound2，其包括编码器 - 解码器架构和位置感知注意机制，可直接将面部图像序列映射到熔化谱图，而无需任何人类注释。提出的Lipsound2模型首先在$ 2400H的$ 2400h多语言（例如英语和德语）视听数据（VoxceleB2）上进行预先培训。为了验证所提出的方法的概括性，我们将在与以前的方法相比，微调在域特定数据集（网格，TCD-Timit）上进行预先训练的模型，以实现对语音质量和可懂度的显着提高扬声器依赖和依赖的设置。除了英语外，我们还在CMLR数据集上进行中文语音重建，以验证对转移性的影响。最后，我们通过微调在预先训练的语音识别系统上产生生成的音频并在英语和中文基准数据集中实现最先进的性能来培训级联唇读（视频到文本）系统。

自我监督学习（SSL）在语音识别方面取得了巨大的成功，而有限的探索已尝试完成其他语音处理任务。由于语音信号包含多方面的信息，包括说话者身份，副语言学，口语内容等，学习所有语音任务的通用表示都具有挑战性。为了解决该问题，我们提出了一个新的预培训模型WAVLM，以解决全堆栈的下游语音任务。 Wavlm共同学习了蒙面的语音预测和预训练。通过这种方式，WAVLM不仅可以通过掩盖的语音预测来保持语音内容建模能力，而且还可以通过语音denoing来提高非ASR任务的潜力。此外，WAVLM还采用封闭式的变压器结构的封闭相对位置偏置，以更好地捕获输入语音的序列排序。我们还将培训数据集从60k小时扩展到94K小时。 WAVLM大型在精湛的基准上实现了最先进的性能，并在其代表性基准上为各种语音处理任务带来了重大改进。代码和预培训模型可在https://aka.ms/wavlm上找到。

最近，蒙面的预测预训练在自我监督的学习（SSL）方面取得了显着的进展，以进行语音识别。它通常需要以无监督的方式获得的代码簿，从而使其准确和难以解释。我们提出了两种监督指导的代码书生成方法，以提高自动语音识别（ASR）的性能以及预训练效率，要么通过使用混合ASR系统来解码以生成音素级别对准（命名为PBERT），要么通过在上进行集群进行聚类。从端到端CTC模型（命名CTC聚类）提取的监督语音功能。混合动力和CTC模型均经过与微调相同的少量标记语音训练。实验表明，我们的方法对各种SSL和自我训练基准的优势具有显着优势，相对减少了17.0％。我们的预训练模型在非ASR语音任务中还显示出良好的可传递性。

视听自动语音识别（AV-ASR）是ASR的扩展，它通常来自扬声器嘴的动作。与仅关注唇部运动的作品不同，我们研究了整个视觉框架（视觉动作，对象，背景等）的贡献。这对于不一定可见的说话者不一定可见的视频特别有用。为了解决这项任务，我们提出了一个新的序列到序列视听ASR变压器（Avatar），该序列是从频谱图和全帧RGB端到端训练的。为了防止音频流主导训练，我们提出了不同的单词掩盖策略，从而鼓励我们的模型注意视觉流。我们证明了视觉模态对2 AV-ASR基准测试的贡献，尤其是在模拟噪声的情况下，并表明我们的模型以很大的边距优于所有其他先前的工作。最后，我们还为AV-ASR创建了一个名为Visspeech的新的现实世界测试床，该床在挑战性的音频条件下展示了视觉模态的贡献。

We show for the first time that learning powerful representations from speech audio alone followed by fine-tuning on transcribed speech can outperform the best semi-supervised methods while being conceptually simpler. wav2vec 2.0 masks the speech input in the latent space and solves a contrastive task defined over a quantization of the latent representations which are jointly learned. Experiments using all labeled data of Librispeech achieve 1.8/3.3 WER on the clean/other test sets. When lowering the amount of labeled data to one hour, wav2vec 2.0 outperforms the previous state of the art on the 100 hour subset while using 100 times less labeled data. Using just ten minutes of labeled data and pre-training on 53k hours of unlabeled data still achieves 4.8/8.2 WER. This demonstrates the feasibility of speech recognition with limited amounts of labeled data. 1 1 Code and models are available at https://github.com/pytorch/fairseq Preprint. Under review.

本文的目标是学习强烈的唇读模型，可以在静音视频中识别语音。大多数事先有效地处理开放式视觉语音识别问题，通过调整在漫步的可视化功能之上的现有自动语音识别技术。相反，在本文中，我们专注于唇读中遇到的独特挑战，并提出量身定制的解决方案。为此，我们提出以下贡献：（1）我们提出了一种基于关注的汇集机制来聚合视觉语音表示; （2）我们首次使用Sub-Word单元进行唇读，并显示这使我们能够更好地模拟任务的含糊不限; （3）我们提出了一种用于视觉语音检测（VSD）的模型，在唇读网络顶部培训。在上文之后，我们在公共数据集训练时获得最先进的LRS2和LRS3基准，甚至通过使用更少的数据量级验证的大规模工业数据集培训的型号。我们最好的模型在LRS2数据集中实现了22.6％的字错误率，这是唇读模型前所未有的性能，显着降低了唇读和自动语音识别之间的性能差距。此外，在AVA-ActiveSpeaker基准测试中，我们的VSD模型超越了所有可视基线，甚至优于最近的几种视听方法。

Audio-visual speech recognition (AVSR) has gained remarkable success for ameliorating the noise-robustness of speech recognition. Mainstream methods focus on fusing audio and visual inputs to obtain modality-invariant representations. However, such representations are prone to over-reliance on audio modality as it is much easier to recognize than video modality in clean conditions. As a result, the AVSR model underestimates the importance of visual stream in face of noise corruption. To this end, we leverage visual modality-specific representations to provide stable complementary information for the AVSR task. Specifically, we propose a reinforcement learning (RL) based framework called MSRL, where the agent dynamically harmonizes modality-invariant and modality-specific representations in the auto-regressive decoding process. We customize a reward function directly related to task-specific metrics (i.e., word error rate), which encourages the MSRL to effectively explore the optimal integration strategy. Experimental results on the LRS3 dataset show that the proposed method achieves state-of-the-art in both clean and various noisy conditions. Furthermore, we demonstrate the better generality of MSRL system than other baselines when test set contains unseen noises.

本文介绍了基于Wav2VEC 2.0的跨语言语音表示学习的大规模模型。我们在128种语言中培训最多2B个公共讲话音频的近半小时的型号的模型，比公共数据的数量级比最大的已知事先工作。我们的评估涵盖了广泛的任务，域，数据制度和语言，都是高低资源。在Covost-2语音翻译基准测试中，我们将先前的最先进的状态平均为7.4 BLEU超过21个翻译方向进入英语。对于语音识别，XLS-R在Babel，MLS，CommonVoice以及Voxpopuli上的最佳已知工作中提高，降低了相对的误差率14-34％。 XLS-R还在Voxlingua107语言识别上设置了新的技术状态。此外，我们表明，具有足够的模型规模，交叉思维预先预测可以在将英语演讲翻译成其他语言时才能优于英语撇印，这是一个有利于单晶的预借预制的设置。我们希望XLS-R可以帮助改善世界上更多语言的语音处理任务。

最近的言语和语言技术的方法预先rain非常大型模型，用于特定任务。然而，这种大型模型的好处通常仅限于世界上少数资源丰富的语言。在这项工作中，我们对来自印度次大陆的低资源语言构建ASR系统进行多种贡献。首先，我们从各种领域策划40个印度语言的17,000小时的原始语音数据，包括教育，新闻，技术和金融。其次，使用这种原始语音数据，我们预先存在于40个印度语言的Wav2Vec样式模型的多个变体。第三，我们分析佩带的模型以查找关键特点：码本矢量的类似探测音素在语言中共享，跨层的表示是语言系列的判别，并且注意力头通常会在小型本地窗口中注意。第四，我们微调了9种语言的下游ASR模型，并在3个公共数据集上获得最先进的结果，包括非常低的资源语言，如Sinhala和Nepali。我们的工作建立了多语言预介质是建立ASR系统的有效策略，为印度次大陆的语言上不同的扬声器建立ASR系统。

Recognizing a word shortly after it is spoken is an important requirement for automatic speech recognition (ASR) systems in real-world scenarios. As a result, a large body of work on streaming audio-only ASR models has been presented in the literature. However, streaming audio-visual automatic speech recognition (AV-ASR) has received little attention in earlier works. In this work, we propose a streaming AV-ASR system based on a hybrid connectionist temporal classification (CTC)/attention neural network architecture. The audio and the visual encoder neural networks are both based on the conformer architecture, which is made streamable using chunk-wise self-attention (CSA) and causal convolution. Streaming recognition with a decoder neural network is realized by using the triggered attention technique, which performs time-synchronous decoding with joint CTC/attention scoring. For frame-level ASR criteria, such as CTC, a synchronized response from the audio and visual encoders is critical for a joint AV decision making process. In this work, we propose a novel alignment regularization technique that promotes synchronization of the audio and visual encoder, which in turn results in better word error rates (WERs) at all SNR levels for streaming and offline AV-ASR models. The proposed AV-ASR model achieves WERs of 2.0% and 2.6% on the Lip Reading Sentences 3 (LRS3) dataset in an offline and online setup, respectively, which both present state-of-the-art results when no external training data are used.

视听自动语音识别（AV-ASR）通过引入视频模式作为其他信息来源来扩展语音识别。在这项工作中，使用说话者嘴的运动中包含的信息用于增强音频功能。传统上，视频模式是通过3D卷积神经网络（例如VGG的3D版本）处理的。最近，图像变压器网络ARXIV：2010.11929展示了为图像分类任务提取丰富的视觉特征的能力。在这里，我们建议用视频变压器替换3D卷积以提取视觉特征。我们在YouTube视频的大规模语料库上训练基准和提议的模型。在YouTube视频的标记子集以及LRS3-TED公共语料库中评估了我们的方法的性能。我们最好的仅视频模型在YTDEV18上获得了34.9％的WER，而LRS3-TED则获得了19.3％，比我们的卷积基线获得了10％和9％的相对改善。在微调模型（1.6％WER）之后，我们实现了在LRS3-TED上进行视听识别的最先进的状态。此外，在一系列关于多人AV-ASR的实验中，我们在卷积视频前端获得了2％的平均相对降低。

最近，先驱工作发现，演讲预训练模型可以解决全堆栈语音处理任务，因为该模型利用底层学习扬声器相关信息和顶层以编码与内容相关的信息。由于网络容量有限，我们认为如果模型专用于音频内容信息学习，则可以进一步提高语音识别性能。为此，我们向自我监督学习（ILS-SSL）提出中间层监督，这将模型通过在中间层上添加额外的SSL丢失来尽可能地专注于内容信息。 LibrisPeech测试 - 其他集合的实验表明，我们的方法显着优于Hubert，这实现了基数/大型模型的W / O语言模型设置的相对字错误率降低了23.5％/ 11.6％。详细分析显示我们模型的底层与拼音单元具有更好的相关性，这与我们的直觉一致，并解释了我们对ASR的方法的成功。

In this paper, we propose a novel multi-modal multi-task encoder-decoder pre-training framework (MMSpeech) for Mandarin automatic speech recognition (ASR), which employs both unlabeled speech and text data. The main difficulty in speech-text joint pre-training comes from the significant difference between speech and text modalities, especially for Mandarin speech and text. Unlike English and other languages with an alphabetic writing system, Mandarin uses an ideographic writing system where character and sound are not tightly mapped to one another. Therefore, we propose to introduce the phoneme modality into pre-training, which can help capture modality-invariant information between Mandarin speech and text. Specifically, we employ a multi-task learning framework including five self-supervised and supervised tasks with speech and text data. For end-to-end pre-training, we introduce self-supervised speech-to-pseudo-codes (S2C) and phoneme-to-text (P2T) tasks utilizing unlabeled speech and text data, where speech-pseudo-codes pairs and phoneme-text pairs are a supplement to the supervised speech-text pairs. To train the encoder to learn better speech representation, we introduce self-supervised masked speech prediction (MSP) and supervised phoneme prediction (PP) tasks to learn to map speech into phonemes. Besides, we directly add the downstream supervised speech-to-text (S2T) task into the pre-training process, which can further improve the pre-training performance and achieve better recognition results even without fine-tuning. Experiments on AISHELL-1 show that our proposed method achieves state-of-the-art performance, with a more than 40% relative improvement compared with other pre-training methods.