NOTE: This issue was resolved on January 20th, 2020. Make sure you update your app version to 0.0.9 on Android and iOS Devices.
We have recently noticed that when you download the audio files on iOS devices, the app downloads, but the audio is not playing.
We are currently working on fixing this issue. Once the issue is fixed, you will need to update your app. Kindly wait for the announcement.
App Development Team.