Adaptive Axonal Delays in feedforward spiking neural networks for accurate spoken word recognition

TL;DR

This paper introduces a learnable axonal delay mechanism in feedforward spiking neural networks, significantly improving spoken word recognition accuracy by adapting delays to temporal data.

Contribution

It proposes a novel method for training axonal delays in SNNs, enhancing temporal processing for speech recognition tasks.

Findings

Achieved 92.45% accuracy on SHD dataset.

Achieved 95.09% accuracy on NTIDIGITS dataset.

Demonstrated the effectiveness of delay training for complex temporal tasks.

Abstract

Spiking neural networks (SNN) are a promising research avenue for building accurate and efficient automatic speech recognition systems. Recent advances in audio-to-spike encoding and training algorithms enable SNN to be applied in practical tasks. Biologically-inspired SNN communicates using sparse asynchronous events. Therefore, spike-timing is critical to SNN performance. In this aspect, most works focus on training synaptic weights and few have considered delays in event transmission, namely axonal delay. In this work, we consider a learnable axonal delay capped at a maximum value, which can be adapted according to the axonal delay distribution in each network layer. We show that our proposed method achieves the best classification results reported on the SHD dataset (92.45%) and NTIDIGITS dataset (95.09%). Our work illustrates the potential of training axonal delays for tasks with complex temporal structures.