This app is using so-called mosquito tones are what you can check
the age of your ear.
■How to use
'Play' button to ring, 'Stop' button to silence. 'Play' pressing
the button, please press the button labeled frequency. The age of
your ear to the age of the most significant frequency of the sound
heard. In manual mode, you are free to raise from 0 to 30kHz sound
operation of the slide bar. With it, you can check over the