An Android app that emits sounds of user-specified frequencies

 

(Screenshot from Huawei Mate 20)

For a web application that has the similar functionality, please refer to my dtc-web-audio-frequency

Instructions

There are three ways to specify the frequency

• type in the frequency
• use the slide bar
• automatically change the frequency range

Source Code

The interface to the phone speaker is the PlaySound class. The supported frequency of sounds is from 1 Hz to 24k Hz.

1. play sound

   PlaySound mPlaySound = new PlaySound();
   mPlaySound.mOutputFreq = your_frequency;
   mPlaySound.start();

   You can change mPlaySound.mOutputFreq during the sound playing

2. stop

   if (mPlaySound != null) {
       mPlaySound.stop();
       mPlaySound = null;
   }

Phones Tested

• Huawei Mate 20
• Google Pixel 2