响了。

You usually put the object first. Say 手机响了 (shǒu jī xiǎng le) for "The phone is ringing." You can also use it alone if the source is obvious. If your alarm wakes you up, just groan 响了... while reaching for the snooze button. It is incredibly versatile and grammatically simple.

Use it the second you hear a notification. It is perfect for interrupting a conversation politely. "Wait, my phone is ringing" becomes 等一下，我手机响了. It works at the office when a timer goes off. It even works when someone rings your doorbell. It is the universal "audio alert" announcement.

Don't use it for continuous sounds like rain or wind. It is for things that *start* ringing or beeping. If someone is talking loudly, don't say they are 响了. That would sound like they are a machine! Also, avoid it for music playing softly in the background. It implies a specific, distinct signal.

In China, people are very responsive to their phones. Saying 响了 is often a social cue to step away. In busy offices, hearing 闹钟响了 (the alarm rang) often means it is time for the sacred midday nap. It is a functional, no-nonsense phrase used by everyone from toddlers to grandparents.

You might hear 一直在响 (yī zhí zài xiǎng) if a phone won't stop. Or 响个不停 (xiǎng gè bù tíng) if it is driving you crazy. If you are asking if it rang while you were out, ask 响过吗?. For a loud, sudden bang, you might use 响了一声. Keep it simple, and you will sound like a local.