Sound earplugs is an application that uses acoustic psychological effects (masking effects) instead of the noise canceller function to reduce ambient sounds that are of concern.

Effective when you can't concentrate on your work, study, programming, etc. due to "too quiet and uncomfortable" "I can't help but worry about ambient sounds" "I'm worried about a specific noise or the next conversation" there is.
However, whether or not the sound earplugs work well depends on the usage environment and individual differences. Please refrain from using if you are concerned about the playback sound of the app.

The specific sound to play can be selected from "radio noise", "forest rain sound", "cafe sound", "night sea", "early morning", "library", "moonlight", and "wind chime".
The playback time of the timer can be specified from "3 minutes, 5 minutes, 10 minutes, 15 minutes, 30 minutes, 1 hour", and the time until the end of playback can be confirmed with the countdown timer on the screen. I will.
Use the volume buttons on the main unit to adjust the volume level.

This app works with the speaker of the main body, but the effect is more clear with stereo earphones and stereo headphones.
Also, pay attention to the volume level so that you do not damage your ears with loud noise.