Underwater Voice Transmission via Piezoelectric Bone Conduction Transducer and Light

Bernhard Uhl

Regarding the safety, underwater communication becomes an important topic for many kinds of diving sports. Currently available (mostly digital) commercial systems, with transmission based on sound waves, are usually not affordable for hobby divers. Moreover for transmitting sound waves a powerful electronic is required which causes difficulties in handling. Available systems on light-based signal transmission often have to be aligned directly with present receivers. This restricts the amount of simultaneous communication partners to only one. Therefore an optical-based light-weighted low-cost system with a range of up to 10 m for diver-diver communication purposes was designed and built as shown in Figure 1. The major goal of this bachelor thesis was the development of the transmitter- and receiver electronic. For both voice input and output bone-conduction of sound as well as piezo-actuators are intended.

Another goal of this bachelor thesis was the improvement of the designed system to provide underwater direction-localization via acoustic source localization.

Keywords: underwater-communication, voice transmission, piezoelectric transducer, acoustic bone conduction

August 07th, 2015

Figure 1: Overview of the complete developed system. R and L are two identical but independent systems. M is a microphone, used by both systems. The right figure shows the system L in more detail. L1 to L5 are representing single transmitter/receiver units.