Questions, bug reports or ideas: ljohnson@cactustimebuilders.com
Open the airport list and tap Restore purchases. You need to be signed in to the same Apple ID that made the purchase.
Check the speaker button in the game is on, the volume is up, and Settings > Accessibility > Spoken Content has a voice installed (Samantha is used when available).
Taxi Trainer is not an FAA product and must never be used for real-world navigation or as a substitute for current official charts and instruction.