Noise Signal

Noise Alert listens to your surroundings through the microphone and alerts you when it gets too loud. You can put the phone in your pocket or leave it on a table with the screen locked — the app keeps watching.

WHY YOU MIGHT NEED IT

• The neighbours behind the wall are having a loud night
• You want to know when the room goes quiet again
• You want to catch the moment someone raises their voice
• You are simply curious how noisy it is around you

HOW IT WORKS

The app measures loudness in decibels and compares it with a threshold you set with a slider. As soon as the noise stays above the threshold for a set time, the alert fires.

THREE ALERT CHANNELS

• Vibration — always works, including with the screen locked
• Sound — a short sharp tone
• Flash — the LED blinks while the app is on screen

You can set the threshold by hand or let the app do it: the "Measure background" button listens to the room for three seconds and tunes sensitivity to your microphone and surroundings. That is more reliable than a fixed value — microphones differ between iPhone models.

HONEST ABOUT LIMITATIONS

The LED flash on a locked screen is a system feature of iPhone. To make it work, turn on "Settings → Accessibility → Audio & Visual → LED Flash for Alerts" and allow notifications for the app. The app cannot enable this setting for you, but it tells you where to find it.

Vibration and sound work with no extra setup.

PRIVACY

Sound is processed on the device only. The app measures the level and immediately discards the data — it does not record, store or transmit anything. The network is not used at all.

While monitoring is running, iOS shows the orange microphone indicator — you always see that the app is working.