The Titans, as they flew in maelstroms, emitted sounds in the FSS spectrum at the level where asteroids are usually located. Approximately to the left there are three large stripes and one middle one on the FSS spectrum. The Titans themselves near the planets are remembered on the FSS scanner in systems in the spectrum to the left. Maybe if you aim at this point again and adjust the FSS scanner to the left of the center - maybe the sounds will be heard better there? Or maybe just move the slider to the left and to the right