Add a button (e.g. to the right of the page title overlaying the lead image) to play the audio recording of the page title (if available).
Behavior
- Show button with audio icon inline with title in lead image area (don't show the icon if the pronunciation clip is not available) (and we're assuming that this will only be available if we're using the Content Service for fetching the page)
- When the button is tapped, play the audio clip in the background. No pause/resume controls are necessary, since these are likely to be very short clips. Nevertheless, we should make sure to stop the audio playback if the user navigates away from the current page (or exits the app).
The icon is called "volume up" in the Material icon set:
https://www.google.com/design/icons/#ic_volume_up
