Do these notifications fire only when the browser is focused, or do they fire when the browser doesn't have focus too? Either way, the full range of 1-5/hour

Do these notifications fire only when the browser is focused, or do they fire when the browser doesn't have focus too? Either way, the full range of 1-5/hour seems way too frequent. Maybe one a day would be tolerable (though I have no motive for tolerating even that.)