Which of the following is considered an acceptable audible notification appliance in a security system?

In a security system, an acceptable audible notification appliance is one that can effectively alert individuals to the presence of a security issue or emergency. Self-contained sirens serve this purpose because they are designed specifically to generate loud sounds in the event of an alarm, thereby drawing attention to the situation.

These sirens can be integrated into a security system to provide immediate and noticeable alerts, ensuring that anyone nearby is made aware of potential danger or unauthorized activities. Due to their emphasis on sound output and their role in alarm systems, self-contained sirens are a widely recognized and commonly used component of security alerts.

While integrated alarm panels can include audible devices, they are primarily control units. Strobe lights are visual notification appliances that complement audible alerts but do not replace them, and manual backup systems might not provide the prompt and effective auditory alert needed in many emergency scenarios. Thus, self-contained sirens stand out as the most appropriate choice as an audible notification appliance in a security context.