International Building Code Section 1207

International Building Code 1207.1

Scope. This section shall apply to common interior
walls, partitions and floor/ceiling assemblies between adjacent
dwelling units or between dwelling units and adjacent public
areas such as halls, corridors, stairs or service areas.

[edit]International Building Code 1207.2

Air-borne sound. Walls, partitions and floor/ceiling
assemblies separating dwelling units from each other or from
public or service areas shall have a sound transmission class
(STC) of not less than 50 (45 if field tested) for air-borne noise
when tested in accordance with ASTM E 90. Penetrations or
openings in construction assemblies for piping; electrical
devices; recessed cabinets; bathtubs; soffits; or heating, ventilating
or exhaust ducts shall be sealed, lined, insulated or otherwise
treated to maintain the required ratings. This requirement
shall not apply to dwelling unit entrance doors; however, such
doors shall be tight fitting to the frame and sill.

[edit]International Building Code 1207.3

Structure-borne sound. Floor/ceiling assemblies
between dwelling units or between a dwelling unit and a public
or service area within the structure shall have an impact insulation
class (IIC) rating of not less than 50 (45 if field tested)
when tested in accordance with ASTM E 492.