loud-bell.ogg
    Copyright: Dr. Richard Boulanger et al
    License: CC-BY Attribution 3.0 Unported
    URL: http://www.archive.org/details/Berklee44v11
    Copied from: https://gitlab.freedesktop.org/xdg/xdg-sound-theme

bell.ogg
    Copyright: Ivica Ico Bukvic
    License: Creative Commons - Attribution 3.0 Unported
    Copied from: https://gitlab.gnome.org/Archive/gnome-audio

clock.ogg
    Copyright: cmorris035
    License: Creative Commons 0
    URL: https://freesound.org/people/cmorris035/sounds/202932/

brown-noise.ogg
    Copyright: NoiseCollector
    License: Creative Commons - Attribution 3.0
    URL: https://freesound.org/people/NoiseCollector/sounds/3948/

metronome.ogg
    Copyright: digifishmusic
    License: Creative Commons - Attribution 4.0
    URL: https://freesound.org/people/digifishmusic/sounds/49115/

