  Detecting anchor's voice in live musical streams is an important
preprocessing for music and speech signal processing. Existing approaches to
voice activity detection (VAD) primarily rely on audio, however, audio-based
VAD is difficult to effectively focus on the target voice in noisy
environments. With the help of visual information, this paper proposes a
rule-embedded network to fuse the audio-visual (A-V) inputs to help the model
better detect target voice. The core role of the rule in the model is to
coordinate the relation between the bi-modal information and use visual
representations as the mask to filter out the information of non-target sound.
Experiments show that: 1) with the help of cross-modal fusion by the proposed
rule, the detection result of A-V branch outperforms that of audio branch; 2)
the performance of bi-modal model far outperforms that of audio-only models,
indicating that the incorporation of both audio and visual signals is highly
beneficial for VAD. To attract more attention to the cross-modal music and
audio signal processing, a new live musical video corpus with frame-level label
is introduced.
