# A Hybrid CNN-BiLSTM Voice Activity Detector Source: [A Hybrid CNN-BiLSTM Voice Activity Detector]() Collection index: [llms.txt]() Data updated: 2026-01-04T03:21:09.647Z Authors: Nicholas Wilkinson, Thomas Niesler Published: 2021-03-05T08:15:36.000Z ## Abstract This paper presents a new hybrid architecture for voice activity detection (VAD) incorporating both convolutional neural network (CNN) and bidirectional long short-term memory (BiLSTM) layers trained in an end-to-end manner. In addition, we focus specifically on optimising the computational efficiency of our architecture in order to deliver robust performance in difficult in-the-wild noise conditions in a severely under-resourced setting. Nested k-fold cross-validation was used to explore the hyperparameter space, and the trade-off between optimal parameters and model size is discussed. The performance effect of a BiLSTM layer compared to a unidirectional LSTM layer was also considered. We compare our systems with three established baselines on the AVA-Speech dataset. We find that significantly smaller models with near optimal parameters perform on par with larger models trained with optimal parameters. BiLSTM layers were shown to improve accuracy over unidirectional layers by $\\approx$2% absolute on average. With an area under the curve (AUC) of 0.951, our system outperforms all baselines, including a much larger ResNet system, particularly in difficult noise conditions. ## Recorded benchmark results A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage. - [Voice Activity Detection on AVA-Speech (test)](): Voice Activity Detection; AVA-Speech (test); AUC-ROC: not recorded. ## Original sources and implementation [Original paper]() [PDF]()