Dan Ellis: Research Projects:

Alarm Sound Detection

Alarms are a very important class of sounds that we encounter in everyday life. They have been specially designed to be distinctive, to attract attention, and to be easily identifiable as alarms even to listeners who have never heard them before.

The problem of automatically detecting alarm sounds is interesting for a number of reasons. Firstly, it will involve a study of the alarm sounds themselves, which could lead to a better understanding of what makes a good alarm sound. Secondly, it could lead to valuable applications, for instance a portable device that could alert a hearing-impaired person to an alarm that might otherwise go unnoticed. Thirdly, it is a relatively tractable example of a much larger class of problems ­ the separation and identification of particular sound sources in real-world environment mixtures ­ that we would like to tackle (i.e. the problem domain often referred to as computational auditory scene analysis or CASA).

Because alarms are meant to be easily heard, we can be optimistic that, in favorable circumstances, we can develop automatic algorithms to detect them. The more significant question concerns the kind of discrimination that can be achieved between weaker alarm sounds in noisy backgrounds, and false alarms arising from the noise. In order to be useful, any kind of automatic device would need to approach the performance of a normal-hearing listener, which is a high standard.

Some preliminary investigations have been conducted into this work, as illustrated in the figure above, which shows a telephone ring being detected against a jazz recording playing in the background. However, a more careful and thorough investigation is required. The project will involve:

This is a neat little project. Assuming this part works out, and we end up with a useful alarm detection system, there are numerous possible follow-ons. I am most interested in generalizing the techniques used to isolate alarm sounds from their background to work for other sound sources in real acoustic environments.

Last updated: $Date: 2000/12/11 17:17:41 $
Dan Ellis <dpwe@ee.columbia.edu>