The growing use of speech at the interface of mobile communication devices and the starting transition from portable solutions to wearable ones will eventually render both the touch-tone keypad and the handset obsolete. However, controlling a device by speech is not always optimal. It is often socially unacceptable to speak to a communication device (for instance, in a meeting, in a public space, or at an office). Besides, the quality of speech recognition drastically varies depending on the level of ambient noise and acoustic characteristics of the environment. To improve the performance of the speech recognizer, most devices featuring speech control require user-driven activation and deactivation of speech input by touch. Unlike personal computers that use sophisticated general touch controls for this purpose, mobile communicators employ a push-to-talk button. As a rule, it is detached from the device.

The project presents an exploration of the space between a push-to-talk button and a full-blown wearable keyboard. A computer mouse was remodeled into a wrist mountable control for a communication device running the client software of Impromptu, an IP-based audio platform for mobile communication and networked audio applications being developed at the Speech Interface Group. Three buttons and a wheel can be used in combination with speech commands or fully substitute for them.

We argue that a device of the type combining low cognitive affordances with an expressive power adequate for many applications can be as useful in the world of mobile communications as the mouse has proven to be in the world of personal computers. A wearable solution comprising a communicator, a headset, and a mouspeak is particularly advantageous in truly mobile contexts where neither general touch input nor video output is possible, since the user needs to dedicate a lot of cognitive resources to the process of world navigation. It also expands the range of situations where it is socially acceptable for the user to interact with the mobile device.