Presenter Name:Andres Elizondo Lopez

School/Affiliation:McMaster University

Co-Authors:Dr. Michael Schutz

Abstract:

Auditory alarms are present in many aspects of daily living, some alarms are useful to convey crucial information in volatile workplaces, and to garner user’s attention. However, these alarms can be problematic; users struggle to detect these alarms unless they are loud, causing problems with speech communication and annoyance. One specific shortcoming of the current design stems from the sounds used, which often feature flat amplitude envelopes. Past studies have found that percussive tones lead to higher detection in low signal-to-noise (SNR) levels (Foley, Under Review). Percussion instruments characteristically have a percussive amplitude envelope. A common percussive instrument, the triangle, “sticks out” among the spectrally rich sounds produced by the other orchestral instruments. Using the musical properties of the triangle, a new set of percussive tones that closely mimic the instrument is synthesized to compare to flat tones for detectability. Triangle tones are comprised of a 5ms rise, 1995ms exponential decay. Flat tones have a 20ms rise, 960ms sustain and 20ms fall. A coordinated response measure is used as a speech intelligibility assessment and signal detection task. Participants follow spoken instructions presented with distractor phrases; throughout the task they indicate if a tone is heard at different SNR levels. Participants reached significantly higher detection with the percussive triangle tones at lower SNRs than flat tones, without compromising speech comprehension. Providing evidence that the acoustic properties of musical instruments can greatly increase efficiency of auditory alarm systems.