UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Warnsis ii : A warning signal identification system for the hard of hearing Dotto, Kim

Abstract

Having examined a number of common warning signals such a telephone rings, microwave oven alarms and continuous tone alarms, a software method, eliminating the need for specialized hardware, was developed for both recognizing known warning signals and learning new signals. The method, called WARNSIS II was first implemented on a PC-compatible computer using a Creative Labs signal acquisition board which provided a base for graphical signal analysis and for the development of algorithms. The algorithms were also implemented on the Texas Instruments TMS320C30 Evaluation Module (EVM) digital signal processing board to demonstrate that the algorithms can be easily ported to smaller, more cost effective platforms. The WARNSIS II system operates in two modes: learning and recognition. In the learning mode a template for a signal is constructed by analysing the signal for spectral and temporal information. The frequency at which the maximum peak in the signal's spectral energy occurs is determined and this value is saved in a template. The duration of the signal burst, as well as the interval time between signal bursts for repetitive signals, are determined and are also saved in the template. In the recognition mode, the spectrum of the incoming real-time signal is analysed to determine if any of its spectral components match those found in the template. If a match is found, timing information is then applied to rule out transients which would generate false alarms The system has demonstrated the ability to recognize warning signals in high background noise environments and to correctly identify multiple overlapping warning signals.

Item Media

Item Citations and Data

Rights

For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.