Since November 2015, two underwater gliders equipped with external hydrophones were deployed in the South Brazilian Bight in order characterize the area's soundscape. Contrasting to standard fixed mooring systems (where flow noise is generated by currents passing by the hydrophones), gliders are subject to noise generated by its own downward and upward motion, which may compromise soundscape characterizations if not properly evaluated. In order to investigate induced flow noise on the hydrophone and its characteristics, 563 hours of acoustic data from the gliders were correlated to the navigation settings. Results can be comparable to previous flow noise descriptions for fixed systems. A high correlation was observed between the glider speed (both vertical and total) and 1/3 octave band levels centered at frequencies below 20 Hz. Estimates of the broadband sound pressure level were accomplished with different lower frequency limits and found to be uncorrelated to the glider speed above 40 Hz.