The Spectroline Marksman from Spectronics is an ultrasonic diagnostic tool that converts and amplifies inaudible ultrasonic sound into audible natural sound. It allows aviation technicians to hear sounds, such as compressed air, vacuum, pneumatic, and other pressurized leaks, that can signify problems. The tool can also be used to check for electrical discharge due to insulation breakdown, carbon tracking, and arcing. The system uses a two-tiered process to ensure accurate diagnosis: first, the receiver converts inaudible sound into audible sound using a process known as heterodyning; then, the receiver’s Sound Signal Technology fine-tunes the audible sound into the natural sound emitted by the defect itself. A 10-bar LED display indicates the intensity of incoming signals.