How much protection do the sound insulation standards give and is this enough?

Social surveys in several European countries have shown that inhabitants of multifamily dwellings are considerably annoyed by noise from their neighbour's activities. This is also in countries where sound insulation minimum requirements exist and have been enforced for many years. It is therefore necessary to establish data on the sound levels of activities in residential buildings and undertake survey comparisons with the responses by inhabitants. Such studies are also relevant to external noise break-in through facades from traffic noise which is related to actions plans according to END. From the data studies and surveys sound insulation requirements may be deduced. In some countries proposals have been developed on a correlation between sound insulation R'w or DnT,w and percentage of people satisfied or annoyed, and classification schemes have been established with decreasing percentage of people annoyed, when applying higher sound classes. These schemes show great differences from country to country, and also the studies and questionnaire surveys have been developed in isolation from one another. This paper will discuss the merits of having different sound insulation classes to meet different needs of activities and quietness in the home and to have verbal explanations of classes to make differences between classes understandable to ordinary people.