I have just purchased the GENKI Vocab Cards app for reviewing vocabulary from the GENKI Japanese textbook. It is a flashcards application. Every card is equipped with a loudspeaker button that is supposed to sound the pronunciation of the card's word or phrase when clicked. However, clicking the button produces no sound.
I have no problem hearing the playback of a Voice Memos recording.
What steps can I take to try and fix this issue?
iOS App: GENKI Vocab Cards, Version 2.2.0
Device: iPhone 7
iOS: 10.3.1 (14E304)
Issue: Pressing the "play/speak" button results in no sound output