Comparison of Feedback Modes for the Visually Impaired: Vibration vs. Audio

Mobile computing has brought a shift from physical keyboards to touch screens. This has created challenges for the visually impaired. Touch screen devices exacerbate the sense of touch for the visually impaired, thus requiring alternative ways to improve accessibility. In this paper, we examine the use of vibration and audio as alternative ways to provide location guidance when interacting with touch screen devices. The goal was to create an interface where users can press on the touch screen and take corrective actions based on non-visual feedback. With vibration feedback, different types of vibration and with audio feedback different tones indicated the proximity to the goal. Based on the feedback users were required to find a set of predetermined buttons. User performance in terms of speed and efficiency was gathered. It was determined that vibration feedback took on average 41.3% longer than audio in terms of time to reach the end goal. Vibration feedback was also less efficient than audio taking on average 35.2% more taps to reach the end goal. Even though the empirical evidence favored audio, six out of 10 participants preferred vibration feedback due to its benefits and usability in real life.