— Command: silence [state|sec]

(none)
Toggles silence monitoring of windows. When silence is turned on and an affected window is switched into the background, you will receive the silence notification message in the status line after a specified period of inactivity (silence). The default timeout can be changed with the silencewait command or by specifying a number of seconds instead of on or off. Silence is initially off for all windows.

— Command: defsilence state

(none)
Same as the silence command except that the default setting for new windows is changed. Initial setting is `off'.

— Command: silencewait seconds

(none)
Define the time that all windows monitored for silence should wait before displaying a message. Default is 30 seconds.