Low-Power Algorithmic Approaches in DSP Implementations
Hearing aid signal processing is a challenging task because of the extreme low-power, highly-constrained cycle performance required. The audio signal processing is always on, and requires complex algorithms and computations. A typical hearing aid will have multi-band analysis and synthesis, automatic feedback cancellation, environment detection and action, automatic gain control, and user interface - and AI is arriving as well. In order to reconcile the two disparate requirements (complexity vs. low power & reduced cycles), various approaches are needed to achieve low power while still providing sophisticated calculations. In this talk, I will discuss a sampling of numerical methods, shortcuts, refactorings, and approximations which significantly lower power in DSP algorithms. This will be an overview which I hope sparks thinking to extend the presented concepts to other low-power algorithmic tasks. While the focus is on algorithms and computations, some of these topics will also touch on implications to HW design, HW vs. FW tradeoffs, and ASIP / programmable DSP core design.