The basic ATIS and ATC voices appear to be recorded with distortion, or the audio of that voices is replayed with distortion. This is most apparent if one listens to ATIS. There is no distortion when using the basic test voices in the GUI of the BeyondATC App. Adjustment of volume levels within th App or using MS Windows 11 sound mixer does not help.
I am a ham radio operator since 38 years and active on VHF as well as on the HF ham bands, and I can tell you that the audio of transmissions of transmitting stations is usually not distorted unless the station significantly overdrives the mic input levels.
I now that there is the feature in the GUI that audio is degraded over distance however this has nothing to do that the actual audio is distorted. I have watched YouTube videos and there seems to be a basic problem.
Just listen the first 20 seconds of this video and you hear that the ATIS audio is overdriven:
Over time the ears get used to it and filter the information but it would be great to have the same clean voices for ATIS and ATC as the basic test voices in the GU