I have been having trouble with video freezing and video transmission link problems on 5.8 G whenever I was flying my Spark (using the RC) and an obstical avoidance warning was received.  Fly Spark up near an object, get the usual warning and the video would freeze until the warning was not present (moved Spark away from the object).  If I went to 2.4 G, the problem went away and video continued normally when avoidance warnings appeared.
I hunted and hunted to try and find the reason.  Surely the problem would go away with the latest firmware updates to Spark, batteries, controller and software update to Go 4.  Got everything updated and sadly the problem continued.  I had always been careful to turn off Bluetooth on my iPhone 7 but the problem continued.

Today, I knew I would be at home alone so I did not take time to put in my hearing aids (Oticon).  These are the newer type of hearing aids that have Bluetooth to sinc to a smart phone.  Started up the Spark, left it on 5.8 G, flew it up to an object, received the usual warning and the video continue to work just fine.  I went and got my hearing aids, turned them on and repeated the test and, sure enough, the video freeze reappeared.

Bottom line, to avoid video freeze and other potential interferance problems be sure to turn of all Bluetooth devices, including hearing aids, when flying your new Spark.  

I sure do hate having to turn off my hearing aids because now I have difficulty hearing the voice prompts.  

Virgil Quick Posted at 2017-7-28 12:00
I sure do hate having to turn off my hearing aids because now I have difficulty hearing the voice prompts.

Interesting indeed.  I connect to the Spark, or Remote, then always put my phone (iPhone 7) in, "airplane mode," then hit the wifi button again.  Wonder if that would help you?  

It appears that the interference is actually coming from the Bluetooth of my hearing aids.

The RC is dual band and works like this (without OTG):
1. RC - AC connection is on  5.8GHz, Phone - RC connection is on 2.4GHz
2. RC - AC connection is on  2.4GHz, the Phone - RC connection is on 5.8GHz.   
This is, of course, pretty much simplified because the mess with reserved bands in EU space, limited power etc.

Anyway, Bluetooth is also using 2.4Ghz. The reason you are not getting permanent interference is because the radio on your phone is transmitting only when there is sound to play on the Bluetooth audio devices, in this case, the warnings. The interference is not coming from your hearing aids but mostly from your phone itself. Basically, your phone is jamming the RC - phone connection on 2.4GHz

good find...  yea the spark uses wifi with the RC and the Phone.. and always a 2.4Ghz signal present. and bluetooth is on 2.4Ghz.  my car caused a lot of interference with my ex-spark because it has a really strong bluetooth signal..made mistake of trying to land on roof of my car and it gto super choppy and cut signal.

wifi is very easily interfered .  also interesting thought..   2.4Ghz has a full wavelength of 31.25mm and 5.8Ghz has a full wavelength of 12.9mm      very very narrow waves that will very very easily get lost at greater distances and absorbed into the air and clouds and anything physical in between as well as very very easily reflected (in fact how wifi works around the house, is mostly secondary signals bouncing around)