Opening Freelancer Companion while running 4.86 causes the sounds to get messed up (sounds like loud radio static). I didn't have this problem with 4.85 or with 4.86 Update 3. However, I did have this problem during the early versions of 4.86 and now it has returned with Update 4. Something that was fixed in Update 3 got broken again in Update 4. Note that closing Companion doesn't solve the problem -- only restarting Freelancer solves it until the next time I open Companion.
I have the same problem with a sound. But i do not care about this.
This problem is really annoying to me, as it prevents me from understanding any transmissions from NPCs which destroys a lot of the RP environment for me. I think the problem is worse now than it was in earlier versions of 4.86, so somebody really broke it this time. Now when I use Companion, I have to take notes on what I'll do with the information, then I have to log-off and restart Freelancer and refer to my notes the next time I play that character, as the sound is too annoying for me to play once I've opened Companion.
Turn off the dynamic updates in FLC. That should stop the processes from interacting.
For the record, I've just noticed this problem too. Curious.