I have been tinkering with several new LokSound V5 decoders recently. There are some useful changes with respect to version 4. Here is one that users may have overlooked.
One Logical Function that can be applied to any function button is 'Fade Out Sound'. It was advertised to allow quieting the loco when entering a tunnel. In version 4 it was only possible to program the amount of fade. In the new version not only can the amount of fade but also the time to fade out (and in) is programmable. So if you set the time period to be maybe 20 or 30 seconds, then if you activate the function as the train is leaving town it fades away quite prototypically. Likewise when it is coming into town deactivate to fade it in.
The CV controlling the time is CV135. The value entered corresponds directly to seconds.
Have fun,
George