transmitter an instrument that sends out slectrical signals Related Articles: Glossary: acoustic fish tagGlossary: sonobuoyHow is sound used to navigate underwater?Acoustic ReleaseAcoustic Fish TagsHow is sound used to measure water depth?How is sound used to monitor and defend harbors?Tutorial: Measure Water DepthIchthyologistHow is sound used to map the seafloor? Chris Knowlton2017-02-26T20:10:02-05:00