Step One:
Listen to the sound file by clicking below sound bar below.  Hum the sound.  The sound is "So" concert G and "Me" concert E.

Step Two:
Play the same sound file again, but this time sing either "So" for the first tone and "Me" for the second tone. 

Sound Bar

   Sound Bar

Step Three "tuning your voice".
  Look at the pictures below.  The below are examples of what you will want to have the tuner show you when you sing "So" and "Me" correctly.

Tuning Page

G Diagram

E Diagram