In the field of Human Machine Interfaces (HMI), there is a potential to convey numerous different messages by non-verbal-sounds. In the eighties, different approaches to the design of information-bearing sounds were proposed. These approaches and corresponding guidelines focused on the acoustical properties of auditory displays. In particular, psychophysical approaches to urgency perception have identified relationships between acoustic parameters and different degrees of urgency perception. We performed an experiment with sounds currently used in automotive HMI. It was found that these sounds are not satisfactory and do not fulfill their intended function, even though some of them match the existing guidelines. Thus, we propose that a new methodology should be used to design more adequate HMIs. This methodology draws on two different theoretical frameworks: acoustics and semiotics (science of signs). In order to investigate the important hypotheses on which the methodology is based, we describe specific experiments that can be used to validate or invalidate the method, when applied to a specific sound design problem. Finally, we discuss the potential use of our new methodology.