“Spindex”: Accelerated Initial Speech Sounds Improve Navigation Performance in Auditory Menus

Abstract

Users interact with mobile devices through menus, which can include many items. Auditory menus can supplement or even replace visual menus. Unfortunately, little research has been devoted to enhancing the usability of large auditory menus. We evaluated a novel auditory menu enhancement called a “spindex” (i.e., speech index), in which brief audio cues inform the user where she is in a long menu. In the current implementation, each item in a menu is preceded by a sound based on the item's initial letter. 25 undergraduates navigated through an alphabetized contact list of 50 or 150 names. The menu was presented with text-to-speech (TTS) alone, or TTS plus spindex, and with the visual menu displayed or not. Search time was faster with the spindex-enhanced menu, especially for long lists. Subjective ratings also favored the spindex. Results are discussed in terms of theory and practical applications.