The HighLight PLUS is a high output LED light source which uses a sensitive contact microphone to extract a patient's fundamental phonation frequency and digitally transform the data into precisely synchronized flashes of light. An internal LED module replaces the costly flashing light bulb saving money over the life of ownership. It can be used as a routine endoscopic light source and will blend seamlessly into most existing office video systems. HighLight PLUS performs stroboscopy in slow motion and stationary. In "auto" the unit automatically calculates the fundamental frequency and synchronizes the light pulses. If a patient has a specific pathology the "manual" mode can be selected and the HighLight PLUS will produce light pulses at a specified frequency. A spectogram screen can be displayed to evaluate the harmonic content.