  Human perception of surrounding events is strongly dependent on audio cues.
Thus, acoustic insulation can seriously impact situational awareness. We
present an exploratory study in the domain of assistive computing, eliciting
requirements and presenting solutions to problems found in the development of
an environmental sound recognition system, which aims to assist deaf and hard
of hearing people in the perception of sounds. To take advantage of smartphones
computational ubiquity, we propose a system that executes all processing on the
device itself, from audio features extraction to recognition and visual
presentation of results. Our application also presents the confidence level of
the classification to the user. A test of the system conducted with deaf users
provided important and inspiring feedback from participants.
