Volume Booster: Louder Sound

An app for when your phone is not loud enough. It raises the sound beyond the phone's own volume, and then measures with the microphone how much louder it actually became.

■ You can measure whether it works
Volume boosters work on some phones and not on others. This one plays a short test tone and shows the difference between boost off and boost on in dB. If almost nothing changed, it says so: "The boost does not seem to work on this phone."

■ One knob
Tap or drag the round knob. It goes from 0 to +15 dB, shown as 0 to 100%. There are also buttons for Normal, +25%, +50%, +75% and Max. It lifts the sound coming out of the phone as a whole: video, music, games and calling apps.

■ It does not cut out
While the boost is on, it stays in the notification bar and keeps working when you switch to another app. Tap "Turn off" in the notification to stop it at once.

■ It looks after your ears and your speaker
The first time you go above 60%, it asks you to confirm. When earphones or Bluetooth are connected, it lowers itself to 30% automatically.

■ No ad breaks while you listen
While the boost is on, and while it is measuring, no full-screen ad is shown. A video ad never stops your music. No limits on how often you can use it, and nothing to buy.

Good for
・Video or music that is too quiet even at full volume
・Calls and online meetings that are hard to hear
・Listening outdoors, in the kitchen or anywhere noisy
・Phones and tablets with a small speaker

How to use it
1. Set the amount with the knob
2. Press "Turn boost on"
3. Press "Measure" to see how much louder it got

What to know
How much it helps depends on the phone, and some phones do not allow apps to boost the sound at all. Raising it a lot can make the sound distort. Loud sound for a long time can hurt your ears and your speaker. Raise it little by little, and turn it down if it sounds harsh. The microphone is used only to read the loudness when you press "Measure". Nothing is recorded or sent.