Sometimes, it’s what you don’t hear that’s just as alarming.

I’m a lifestyle and pet writer with over a decade of experience in copywriting, covering viral animal moments, well-being topics, and lifestyle trends.

"Even in the city, if the crowd suddenly falls silent, shut the hell up and pay attention. Sometimes it’s something stupid. Every once in a great while it’s something you really, absolutely need to be aware of."

In most areas, a siren with a steady tone indicates a severe weather emergency, such as a tornado or tsunami, but a siren with a rising and falling pitch indicates a national security emergency such as a terrorist attack or nuclear bomb.

"I literally experienced this in the middle of a hurricane. A tree went down and knocked an energized line into our service (or something). Power went out, but we noticed a weird humming. It turned out power was coursing through the house and had somehow energized our plumbing, which started a fire in the crawlspace. Firefighters responded (did I mention this was in the middle of a frreakin' hurricane?) and later told us we'd have probably been electrocuted if we'd decided to use the toilet before bugging out."

"Learned that in the Army. The only word we used instead of 'duck' was 'INCOMING!'"

"During the ballistic missiles alert, we headed up the volcano because the tsunami wave was about the only thing we could escape. During the 20 minutes or so of uncertainty, I called family."

"Former fire alarm inspector here. It amazes me how many people hear an alarm and just sit there asking, 'Is it a false alarm?' I was once inspecting a high-rise when the alarm on another floor activated. The building manager came over the radio, sounding annoyed. I told him I was several floors away and that he needed to send someone to investigate immediately. It turned out that a storage closet was on fire because someone had been smoking inside and failed to extinguish their cigarette properly. Fortunately, the fire was still small enough to be handled with an extinguisher, but imagine what could have happened if it had been more serious.

Always take an alarm seriously. If you evacuate 19 times because of false alarms, but the 20th alarm saves your life because it’s real, then every evacuation was worth it."

This could indicate a school of fish, or even chum, in the water, which can attract sharks.

"It's a muster alarm: the signal that everyone has to go to the muster point, where you'll put on life jackets and prepare to abandon ship if necessary."

"Venting high-pressure lines sounds like a jet engine."

It could mean a tree branch above you is about to break.

Note: Responses have been edited for length and/or clarity.