Binaural In-Ear Monitoring system designed to alleviate the issues of isolation expressed by live performers as a result of background attenuation provided by current models of In-Ear Monitors (IEMs). The concept of dynamic monitor mixing is presented, with sensor input affecting parameters within the mix to mimic some of the real world characteristics of acoustic performance. Features were identified by analysing the problems with current models of IEMs, and the needs of musicians, ascertained from interviews and surveys. The system consists of a wearable gyroscopic headband that tracks the head orientation of the user and a distance tag. The tag interacts with Ultra-Wideband (UWB) Radar sensors deployed at the boundaries of the performance space. The hardware integrates with an application deployed within the visual programming language, Max 8 (Cycling74 2020) while using the Spatial Workstation Virtual Studio Technology (VST) plugin as an audio engine to provide 3D binaural audio. The system combines these elements to dynamically pan the mix as the user turns their head, while automatically adjusting the volume levels of sound sources in the mix as the user moves away or towards them, also mimicking elements of an acoustic environment. These dynamic changes allow the performer to experience the space around them, making the performance feel more natural.