Set up text-to-speech
If you select tap elements in Calendar Clock, the app speaks what that element has to show. Whereas the Calendar Clock Administrator app does not contain any settings regarding this feature, you can still set up several things about it yourself.
When an app uses text-to-speech, they use the models provided by the device itself. As such, if you want to customize the voice or speed of the speech, you should visit your device settings.
iOS
Go to Settings -> Accessibility -> Spoken content. In this screen, you can set up the voice used for each language, and you can set up the speed with which these voices speak. We recommend to leave the other settings as-is to prevent clashes with how Calendar Clock handles the text-to-speech.
Android
Go to Settings -> Accessibility -> Text-to-speech.
On this page, you can already set up the speed of the text-to-speech. If you also want to change the voice, you most likely have to tap the settings icon on the right of the text-to-speech engine. If there are multiple engines showing, you can experiment which engine provides the best voices.
If you prefer another voice that is not shown in your settings, you can download additional voices on the Google Play Store. For instance, you can use Acapela TTS voices (not sponsored).