Six deep learning architectures — GRU, LSTM, LSTM-GRU, and three custom Transformer variants — trained from scratch to classify industrial motor audio into three operational states.
This project classifies the operational state of an industrial motor from raw .wav audio. Six architectures are trained and compared end-to-end on log-mel spectrogram features extracted at 16 kHz. A live Streamlit app supports single-model inference, configurable ensemble inference, and full audio visualization.
Why six models?
This is a comparative study across recurrent and attention-based architectures for audio classification. Training all six on identical features and evaluating them individually and in ensemble isolates the contribution of architecture choice vs. positional encoding strategy.
Why RoPE, Sinusoidal, and Relative PE?
Three fundamentally different approaches to position information: RoPE encodes position in the rotation of Q/K vectors (relative, no added parameters); sinusoidal adds fixed absolute position to the input; relative PE learns a bias over pairwise token distances. Comparing them on the same encoder backbone isolates their effect.
Why log1p + z-score normalisation? log1p compresses the large dynamic range of raw mel energies. Per-clip z-score normalisation makes the model invariant to recording loudness, which varies significantly across motor operating conditions.
Why bidirectional RNNs?
For classification (not streaming), the full temporal context is available at inference time. Bidirectional encoding gives each timestep access to both past and future frames, improving the quality of the final hidden state used for classification.
👤 Author
Jimmy Edifon Emmanuel (Eddy)
AI & Computer Vision Engineer · Lagos, Nigeria