The Strava app can provide real-time audio feedback on segment performance (for runs and rides) as well as split time updates (for runs only).
To enable Audio Announcements
Select Record from the bottom navigation menu.
Select the gear icon in the upper right-hand corner and Audio Cueson the next page.
From here, you enable start/stop/pause announcements for runs, rides, and walks.
You can also enable announcements for every half mile or kilometer, or every full mile or kilometer (depending on the units of measure set in your preferences). This option is only available for run activities.
Try reinstalling the Strava app and restarting your phone.
Double-check that your audio announcement settings are still enabled. Occasionally, your recording settings will be reset if you log out of the Strava app.
Ensure that your media volume, not just your ringer volume, is turned up to an audible level.
Android phones often have three or four settings for volume. Try turning them all up.
iPhones have a control center where you can control media volume. To access the control center on iPhone X and later, swipe down from the top-right corner of the screen. On other models, swipe up from the bottom edge of the screen.
On Android phones, check your Text To Speech language options and confirm the preferred engine matches your system's language preference.