PyAWNeS-Codec: Speech and audio codec for ad-hoc acoustic wireless sensor networks

Existing hardware with microphones can potentially be used as sensor networks to capture speech and audio signals for the benefit of better signal quality than possible with a single microphone. A central pre-requisite for such ad-hoc acoustic wireless sensor networks (ASWNs) is an efficient communication protocol with which to transmit audio data between nodes. For that purpose, we present the world's-first speech and audio codec especially designed for ASWNs, which has competitive quality also in single-channel operation. To ensure quality in the single-channel scenario, it closely resembles conventional codecs of the TCX-type, but extended with features to facilitate multi-device operation, including dithered quantization, delay estimation and compensation, as well as multi-channel post-filtering. The codec is intended to become a baseline for future research and we therefore provide it as an open-access library. Our experiments confirm that performance is in the same range as recent commercial single-channel codecs and that added devices improve quality.