Thicker walls can disappoint. Although adding mass generally reduces sound passing through a partition, small openings around doors and electrical outlets can let airborne noise bypass that investment. Sound finds another entrance. Where a door fails to meet its frame, the room's acoustic performance may depend less on masonry than on the narrow strip beside it.
The arithmetic favors leaks. Under the mass law, heavier partitions generally offer greater transmission loss, meaning less sound energy passes through them, but an opening can sharply reduce the performance of the complete assembly. Thickness earns no exemption. Because sound travels through connected air spaces, gaps beneath doors and unsealed penetrations around electrical boxes can carry speech or television noise into an otherwise substantial enclosure. Absorption is another matter. Soft furnishings and foam panels can reduce reflections inside a room, but they do not substitute for closing the routes through which outside sound enters.
Repairs deserve the first hearing. Before commissioning another layer of wallboard, inspect door seals, thresholds and service penetrations, then choose treatments that preserve ventilation, fire protection and electrical safety. Details govern the result. Appropriate perimeter seals and door-bottom seals can address door leakage, while electrical-box treatments should follow applicable requirements and manufacturer instructions rather than improvised stuffing. Some noise takes detours. If vibration travels through connected floors, ceilings or framing, sealing visible cracks alone will not resolve it, and an acoustic assessment may prevent wasted work. The wall stands thick and silent; the unfinished edge keeps speaking.
