As reported by Timothy J. Crone and associates in PLoSOne, deep-sea hydrothermal vents produce a variety of sounds. Their recordings are "the first unambiguous field recordings showing that these vents radiate significant acoustic energy."
The Sound Generated by Mid-Ocean Ridge Black Smoker Hydrothermal Vents.
Timothy J. Crone, William S.D. Wilcock, Andrew H. Barclay, Jeffrey D. Parsons, School of Oceanography, University of Washington, Seattle, Washington, United States of America.
"Hydrothermal flow through seafloor black smoker vents is typically turbulent and vigorous, with speeds often exceeding 1 m/s. Although theory predicts that these flows will generate sound, the prevailing view has been that black smokers are essentially silent. The sounds contain a broadband component and narrowband tones which are indicative of resonance."
Listen to the audio files on T. J. Crone's web site @ Univ. of Washington School of Oceanography.