As one of the most advanced helmet and headset testers on the market, the HT-4 evaluates both high- and low-impedance headsets and flight helmets. It measures high- and low-impedance microphone sensitivity using a dedicated SPL (Sound Pressure Level) mode and supports high-impedance fixed-wing headsets equipped with Lemo, XLR-5, or twin-plug connectors.
Additionally, the HT-4 supplies operating voltage to aircraft-powered Active Noise Reduction (ANR) headsets, monitors their current draw, and automatically limits the current to a safe level while triggering an audible alarm upon detecting an overload.
It also tests ground support headsets used in ramp operations, deicing, pushback, and maintenance applications—across both wired and wireless configurations.