HIC or Hi-Cut Filter

HIC: This is the Hi-Cut Filter, once this function is enabled, the radio
will cut out high-frequency noise in the receiver circuit. Higher frequencies make up a good portion of what we often refer to as White noise (static); therefore, the Hi-Cut filter eliminates some of that awful static. It also makes it much easier to understand what someone is saying; without the filter, their signal would be much more challenging to hear. Use is dependent on reception conditions and personal preference, but this is a feature many people find they enjoy.