Liverpool Victoria HQ
Meeting rooms used for highly confidential discussions were fitted out by interior designers without any consideration for acoustics. Therefore even though they looked ok aesthetically there was considerable leakage.
The walls were injected with acoustic polyurethane insulation at intervals of every half metre. The insertions made good afterwards. The perimeter above the suspended ceilings were also blocked with barrier and acoustic sprayed polyurethane insulation. Result being a complete success. Db and actual physical noise dramatically reduced.