Insulating one house against aircraft noise

A house near Manchester Airport has been insulated against aircraft noise and measurements were made to establish the usefulness of different methods. It was found that domestic quality dual glazing gives an insulation of about 40 dB(A), glass fibre laid in the loft gives an insulation increase of about 4 dB(A) compared with the bare ceiling, and extra boarding in the loft gives no benefit, probably because the existing lath-and-plaster ceiling is fairly heavy and so gives adequate insulation. The insulation can be increased further by installing heavy glazing, but that would normally be prohibitively expensive.