Scientists detect 'resonant hum’ permeating the universe from gravitational wave data Study authors suspect the low-frequency signal might be coming from gravitational waves, which serves an indicator of cosmic activity. Jan 22, 2021 12:09:19 IST Scientists may have, for the first time, heard the gravitational wave background or resonant 'hum' that permeates the Universe for the very first time. North American Nanohertz Observatory for Gravitational Waves (NANOGrav) detected the sound. The findings from the observations were published in the Astrophysical Journal Letters. In the research, scientists analysed data over a span of 13 years. Researchers studying the signals from distant pulsars, made use of radio telescopes to collect statistics that may indicate the effects of gravitational waves.