Current speech synthesis technology is difficult to understand in everyday noise situations. Although there is a significant body of work on how humans modify their speech in noise, the results have yet to be implemented in a synthesizer. Algorithms capable of processing and incorporating these modifications may lead to improved speech intelligibility of assistive communication aids and more generally of spoken dialogue systems. We describe our efforts in building the Loudmouth synthesizer which emulates human modifications to speech in noise. A perceptual experiment indicated that Loudmouth achieved a 7% gain in intelligibility compared to a standard synthesizer in noise. Categories and Subject Descriptors J.3 [Computer Applications]: Life and Medical Sciences Health General Terms Algorithms, Design, Experimentation, Human Factors Keywords Speech Synthesis, Text-to-Speech Synthesis (TTS), Augmentative and Alternative Communication (AAC)