US Patent 6888457 Monitoring of user response to performances

A portable apparatus for monitoring the reaction of a user to a performance contains one or more sensors for detecting an indirect user response to the performance and a user interface enabling the user to provide a direct user response to the performance. A processor in the portable apparatus is programmed to provide a user reaction signal comprising a combination of the indirect user response and the direct user response to the performance. This user reaction signal may be transmitted to to remote apparatus. A monitoring system using such portable apparatus, and a music playing system using such a monitoring system, are also described.