alarm
alert
alertness
attention
bell
business
businessman
call
caution
communication
concept
control
crisis
danger
deadline
doorbell
emergency
equipment
evacuation
fire
help
jingle
loud
man
metal
morning
notification
panic
protection
reminder
rescue
response
ring
ringer
ringing
safety
security
service
sign
signal
siren
sound
symbol
urgency
urgent
vintage
wake
warn
warning
watch