Scrolling Through Time: Improving Interfaces for Searching and Navigating Continuous Audio Timelines

Existing work has produced a variety of techniques to improve interfaces for navigating an audio timeline. These interfaces typically map user input to either a change in play rate, or playback position. Audio feedback while scrolling at arbitrary rates can be provided by: skipping immediately to the new position in the audio; resampling the audio, which introduces pitch-shifts; timestretching the audio to preserve the pitch; or not at all. We conducted a series of user studies to examine the effects of input and feedback type on targeting performance. Position control was found to be, on average, 15–19% faster than rate control when searching for targets 90 to 100 seconds away in the audio timeline. Time-stretching was found to be the best choice in most scenarios, but skipping, and, for specific user groups, resampling, should be used for precise targeting tasks where the audio play rate falls below one-tenth nominal speed.