A low-power accelerator for the SPHINX 3 speech recognition system

Accurate real-time speech recognition is not currently possible in the mobile embedded space where the need for natural voice interfaces is clearly important. The continuous nature of speech recognition coupled with an inherently large working set creates significant cache interference with other processes. Hence real-time recognition is problematic even on high-performance general-purpose platforms. This paper provides a detailed analysis of CMU’s latest speech recognizer (Sphinx 3.2), identifies three distinct processing phases, and quantifies the architectural requirements for each phase. Several optimizations are then described which expose parallelism and drastically reduce the bandwidth and power requirements for real-time recognition. A special-purpose accelerator for the dominant Gaussian probability phase is developed for a 0.25µ CMOS process which is then analyzed and compared with Sphinx’s measured energy and performance on a 0.13µ 2.4 GHz Pentium 4 system. The res...

• Type: Conference
• Year: 2003
• Where: CASES
• Authors: Binu K. Mathew, Al Davis, Zhen Fang
• Keywords: CASES 2003, Real-time Recognition, Special-purpose, Speech Recognition