2min chapter

99% Invisible cover image

Mini-Stories: Volume 15

99% Invisible

CHAPTER

The Loudness of Emergency Sirens

In 1912, fire engine sirens reached about 96 decibels when measured 11 feet away. In 1974, it reached 114 decibels at that same distance. Bianca Bosker recently looked at the sounds of modern day sirens and found they reached up to 123 decibels in 2019. That might not sound like a big increase, 96 to 114 to 123, but that's on a logarithmic scale. Every 10 decibels is 10 times the sound pressure to the ears,. And twice as loud in our experience of hearing it.

00:00

Get the Snipd
podcast app

Unlock the knowledge in podcasts with the podcast player of the future.
App store bannerPlay store banner

AI-powered
podcast player

Listen to all your favourite podcasts with AI-powered features

Discover
highlights

Listen to the best highlights from the podcasts you love and dive into the full episode

Save any
moment

Hear something you like? Tap your headphones to save it with AI-generated key takeaways

Share
& Export

Send highlights to Twitter, WhatsApp or export them to Notion, Readwise & more

AI-powered
podcast player

Listen to all your favourite podcasts with AI-powered features

Discover
highlights

Listen to the best highlights from the podcasts you love and dive into the full episode