FEATURE: Accessibility Consideration: Alternative output for accessibility purposes and retrofits e.g. Relay output to control visual signage

[mofosyne]

You may also want to consider having two different options:

• Relay output to control external mechanical bells (if it's a retrofit)
• Relay output to control dedicated 'visual bell' alarms for deaf students to see

Source: https://en.wikipedia.org/wiki/School_bell

Schools for the hearing impaired use alternative signaling methods, for example sign language from the teacher and lights that illuminate when the public address/bell is sounding.[3]