If the audio in Avaz is not working, check the following:

  1. Check if the iPad volume is working, through iPad Audio settings. Check if the audio is present in other apps / music from the iPad. If it is not, then press the Volume buttons on the side of the iPad, to increase the volume. For more information, click here - How to increase the volume in the iPad.
  2. If you are using Avaz AAC, the subscription version of Avaz, the Avaz trial / subscription may have expired. On expiry of trial / subscription, the voices will not work, until you purchase a subscription. 
  3. Check Avaz Audio settings
Sometimes the Avaz audio may have been set to a setting where every selection does not speak the word out on selection. But this can be changed based on the child's needs. 

Tap Menu > Settings (Screenshot below) 
    Scroll down to Audio Settings and tap the What to Speak button. (screenshot below)

Select Speak Everything if you want all selections to be spoken. (screenshot below))

Related articles 
Avaz FAQ:  
How to mute words and speak only Message box : audio settings