You can find out how much your child or elderly person can hear.

Select "Volume Control" from the menu and set the barking of dogs and cats in 3 levels in advance.
On the main screen, you can make a cry with the "High", "Medium", and "Low" buttons.
You can listen to the barking of dogs and cats from the smartphone or tablet, and check the condition of the ears by hearing or not.

If you use a keyboard such as Bluetooth, you can use it like a remote control, so you can make sounds with your smartphone on their ears.