The Sensorcom MicroBuds are designed to combine a high quality, acoustically compensated ear monitor with a generic ear plug for use under crash helmets for motorcyclists and in ear monitoring systems for musicians. They are supplied with foam and soft-silcon eartips that will self-form to the shape of the ear; the choice of type personal preference. To compensate for differences of ear-canal volume, a set of graduated low-frequency compensation filters have been designed to provide the optimum bass response. Four different sizes are supplied and selected empirically on the basis of personal preference. It is important to select the most appropriate filter size by listening to a familiar piece of music. In some cases – for pitching or click-track – it may be desirable to close the port completely: this sets the driver to produce the least amount of low frequencies.