In response to Missile Lock Sound affected by vehicle attenuation BIS came up with an ingenious solution (see parent task) which was to change the audio source of the lock-on sound to radio so that it would be listenable at all times.

However this brings a major problem, since most people find an utter annoyance the automatic radio chatter of "Regroup" or "MAN 75 METERS SOUTH EAST" and things like "GRID 1 5 6 1 3 0 OVER" many simply disable radio sound as it completely useless and simply annoying, resulting in the Lock On sound also ending up being muted and misjudged as a bug with the helicopters/planes or a sound mod.

Thus I'd suggest you try find a better solution such as changing the audio source of the Missile Lock alarm once again, or simply adding a feature that mutes radio chatter.
This latter option would actually be appreaciated in a greater range of problems.