C-e H o provides five global Omnivox volumes: main tones and earcons, and notification speech, tones, and earcons. Each is an integer percentage 0–100; 100 is normal, zero silences that component. For example, notification speech 35 and earcons 70 emphasise brief cues over messages.
Shift-left/right adjusts the selected volume by five; RET enters exactly. Changes apply to subsequent audio without restarting; already prepared audio keeps its old level. S saves these five volumes, not routing or spatial settings. Replacement and reconnected Omnivox processes receive current levels.
Independent notification levels need the separate process selected by Automatic, Left, Right, or Both channels. Main-output routing/fallback shares main-process levels. Earcon volume applies to Omnivox-played sounds, not external players or other speech backends. Zero volume does not disable notification recording.