For desktop browsers there are addons available to boost sound: https://addons.mozilla.org/en-US/firefox/addon/600-sound-volume/ https://addons.mozilla.org/en-U

For desktop browsers there are addons available to boost sound: https://addons.mozilla.org/en-US/firefox/addon/600-sound-volume/ https://addons.mozilla.org/en-US/firefox/addon/600-sound-vol... Not sure about mobile.