Which of the following is not an acoustical defect?

The maximum rate of air change is ______

In the acoustical design of a studio, the ratio of height, breadth and length of the studio should be _____

The unit of absorption is ________

The sound insulation of plastered solid brick masonry walls varies as ______

In winter, it becomes necessary to supplied slightly _____ air to the inside of the building.

Rock wool comes under which of the following classifications of absorbents?

The term _____ is used to mean the free passage of clean air in a structure.