An auditory signal should be used to alert the user to the existence of a new alarm, or any other condition of which the user must be made immediately aware.
Additional Information:
Auditory cues should be provided for all new alarms under normal operating conditions. However, under off-normal conditions where high alarm density exists, the designer should consider suppressing the auditory signal for those alarmed conditions that (1) do not require immediate response and (2) do not indicate a challenge to plant safety and technical specifications. For example, audio signals associated with clearing alarms might be omitted under certain circumstances. This will prevent operators from being distracted by less important alarms while attending to more significant ones. Some designs may have a timed audible signal rather than one that is continuous until acknowledged. In this case, see the guideline for reminder audible signals, below.