  Convolutional neural networks (CNN) are one of the best-performing neural
network architectures for environmental sound classification (ESC). Recently,
temporal attention mechanisms have been used in CNN to capture the useful
information from the relevant time frames for audio classification, especially
for weakly labelled data where the onset and offset times of the sound events
are not applied. In these methods, however, the inherent spectral
characteristics and variations are not explicitly exploited when obtaining the
deep features. In this paper, we propose a novel parallel temporal-spectral
attention mechanism for CNN to learn discriminative sound representations,
which enhances the temporal and spectral features by capturing the importance
of different time frames and frequency bands. Parallel branches are constructed
to allow temporal attention and spectral attention to be applied respectively
in order to mitigate interference from the segments without the presence of
sound events. The experiments on three environmental sound classification (ESC)
datasets and two acoustic scene classification (ASC) datasets show that our
method improves the classification performance and also exhibits robustness to
noise.
