We seek to investigate how co-located group brainstorming could be enhanced through computational tools that leverage gestures and voice cues. To pursue this goal we are developing a computer mediated brainstorming environment that utilizes reality-based interaction techniques and sensor-driven Hidden Markov Models (HMMs) tracking group engagement to computationally augment existing brainstorming practices. In this paper, we report the results of a preliminary user study of brainstorming practices that indicate that gesture and voice data can serve as signals for group brainstorming success. Keywords Brainstorming, Gestures, Voice Analysis, Innovation ACM Classification Keywords H5.3 Group and Organization Interface: Computer supported cooperative work