If your field meter no longer receives audio from HD TV channels, you need to purchase the HD AUDIO DOLBY+ SW application, available only for RECENT ROVER instruments with HW enabled.
Without this application, by selecting a TV program broadcast with DOLBY AC3-AC3E-DD+ audio encoding, (example in figure 1) you will not be able to listen to the audio:
Figure 1: Example of HD TV channel broadcast with DOLBY AUDIO AC3 sound
NOTE: The MENU (written and graphic) in the following F.A.Q. may vary from model to model and depending on the installed SW version.