<P><EM>The Routledge Companion to Interdisciplinary Studies in Singing, Volume I: Development</EM> introduces the many voices necessary to better understand the act of singing¿a complex human behaviour that emerges without deliberate training. Presenting research from the social sciences and humanities alongside that of the natural sciences and medicine alike, this companion explores the relationship between hearing sensitivity and vocal production, in turn identifying how singing is integrated with sensory and cognitive systems while investigating the ways we test and measure singing ability and development. Contributors consider the development of singing within the context of the entire lifespan, focusing on its cognitive, social, and emotional significance in four parts: <BR></P><UL><P><LI>Musical, historical and scientific foundations </LI><LI>Perception and production</LI><LI>Multimodality</LI><LI>Assessment</LI><P></P></UL><P></P><P>In 2009, the Social Sciences and Humanities Re