AMNet: Introducing an Adaptive Mel-Spectrogram End-to-End Neural Network for Heart Sound Classification.

The cardiovascular diseases (CVDs) cause tremendous deaths yearly. The Mel-spectrogram is widely used as a tool to analyse the heart sound, which facilitate a cheap and efficient diagnosis of CVDs. Nevertheless, the amplitude and frequency responses of the Mel filter banks remain constant, limiting its function to frequency selection. We propose an adaptive Melspectrogram end-to-end neural network (AMNet) for a better characterisation and classification of heart sound in the work. The core of the adaptive Mel-spectrograms (AMel) lies in an adaptive Mel filter banks whose frequency characteristics remain the same as the original Mel-spectrogram (OMel) and amplitude is learnt by the backropagation algorithm. The AMNet learns the raw audio representation directly and outputs the classification results. It reaches 43.5% Unweighted Average Recall (UAR) and surpasses the model with the OMel and the baseline by 6% UAR. It is demonstrated that the AMel characterises the heart sound more effectively.