M20 Soundproofing - Can I wallpaper over it?

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Hello. I wonder if the M20 AD rubber panels may be effective sound suppressors if covered with wallpaper rather than plasterboard? I live in a four-in-a-block upper flat in Dundee Scotland and the brick separating wall between living rooms allows the noise of talking, coughing and most recently, because of a new tv next door that may be placed near to the wall, quite loud tv noise that interferes with my own which is at a moderate level. The person next door is quite elderly and may be a bit deaf, and, as this has only now become an issue after 20 years of living next door to one another, it may be the new more powerful tv technology is partly to blame as well.

I also wonder if there are any contractors locally that could do the necessary work for me. The rubber panels I could probably cut to shape and stick to the wall, but the plasterboard is another level of difficulty that I'm not really up to. The cost factor is another issue, which is why I wonder if my idea would be of any use.

The wall that separates is brick, and, to complicate matters, a fireplace and communal chimney breast stands out in the middle of this wall. The same protusion exists on the opposite neighbour's side. So far as I can make out, there is no greater emission of noise from the chimney than elsewhere, and I am hoping that the problem lies on the walls either side of it, but it is difficult to tell as the whole wall seems enveloped in sound, but perhaps this is as a result of the merging of the sound from either side of the chimney breast? The separating wall does not go right up to the apex of the roof, but I do not sense that there is any real noise coming in from the roof area. The other neighbours have bought their flats. I am the council tenant.

I had thought of requesting the council do something, but even if they did they might well install something that was useless so far as sound suppression is concerned, and be difficult to rectify subsequently.

I would be grateful for any suggestions.