Optical Microphone and Spectrum Analyzer

Record sounds and vibrations from a distance and analyze frequency content

ECE 4760: Final Project

Jonathan Kaufman

Brian Stern

We implemented an optical microphone which converts distant vibrations, including sound, to an audio signal. Measuring the reflection of a laser beam from windows or glass, it possible to hear sounds near the target. The system also includes frequency spectrum analysis with a real-time display and user-configurable ranges, and it also has an output for headphones to monitor the signal. This may be useful, for example, to the hearing-impaired for listening to a lecturer from a distance in an auditorium. Apart from the listening to speech, this can be used to get an audio signal out of anything that can vibrate and reflect a laser beam. This includes measuring vibrations in buildings for resonance feedback, which would show a peak in the spectrum.