Understanding and improving the identification of concurrently presented earcons

The use of sound to communicate information as part of a user interface has been an active research area for several years. Research has shown that sound can be concurrently presented to users to increase the bandwidth and rate of data presentation. However, when sounds are concurrently presented, they may interfere with each other, such that determining the data encoded in the sound becomes difficult. Modifications to the sounds can help to avoid such interference, but due to the nature of the sounds the impact of the modifications may be constrained. This thesis investigates such interaction with concurrently presented earcons. One experiment investigates how the identification of earcons is affected by the number concurrently presented. It was found that increasing the number of earcons concurrently presented lead to a significant decrease in the proportion of earcons and their attributes successfully identified by participants. With identification falling from 70% correct for one presented earcon to 30% for four concurrently presented earcons. A second experiment identified how modifications to the design and presentation of concurrently presented earcons affected their identification. It was found that presenting each earcon with a unique timbre as well as introducing an onsettoonset delay of at least 300ms caused a significant improvement in earcon identification, and the timbre encoded attribute of earcons. However overall identification levels remained low at around 30%. Two further experiments investigated the impact of spatialisation on concurrent earcon identification. They showed that spatial presentation of earcons which did not incorporate the findings of the previous experiment significantly improved identification of earcons and the register encoded earcon attribute, over earcons that were not spatially presented but did incorporate the findings of the previous experiment. Another experiment showed that spatial presentation of earcons which incorporated the unique timbre and 300ms onsettoonset modifications significantly improved the identification of the timbre encoded earcon attribute, although overall identification remained low. These four experiments yielded a set of guidelines for concurrent earcon presentation. Due to the nature of those experiments however, a further experiment was conducted to determine the impact of the guidelines on more ecologically valid tasks. A set of modified and unmodified earcons which represented entries in a mobile diary system were compared. Overall task accuracy remained low, although participants rated the modified earcons to require significantly less subjective workload.

Level dc:type.qualificationlevel

PhD

Grantor dc:publisher.institution

University of Glasgow

Year dc:date.issued

2004

Author dc:creator

• McGookin, David Kerr

• QA75 Electronic computers. Computer science

Language dc:language

en