The Mayor's Ambient Noise Strategy - Greater London Authority

The Mayor’s Ambient Noise Strategy Mayor of London 29
22 Data is based on responses from local authorities, and is dependent on
numbers of authorities responding. Response rates vary from year to year,
and different boroughs, experiencing different patterns of complaint, may
respond in different years. This should not be interpreted as a strict time
series when assessing trends.
23 Data on complaints or service requests to Borough Environmental Health
Departments need to be interpreted with care. The number of complaints
is not the same as the number of events which might theoretically give
rise to a complaint. If the quality of the service on offer increases, the
number of complaints can increase rather than decrease. If people receive
rapid responses to complaints about one type of noise, more service
requests may be received and handled on that subject than on others.
People may complain less about some sources of noise if it appears that
the local authority noise service can do little about them. Some people in
some areas may be more likely to register a complaint than others.
Differences in the way authorities collect data on complaints make
comparisons difficult. Data definitions and collection methods may be
revised, see ‘Noise Management Guide’ - Guidance on the Creation and
Maintenance of Effective Noise Management Policies and Practice for
Local Authorities and their Officers - Consultation Draft, Temple
Environmental Consultants Ltd on behalf of Defra and CIEH. June 2003,
referring to work by Faber Maunsell for Defra and CIEH. See
http://www.cieh.org/research/environment/noisemanagementguide.htm
24 It should be noted that these surveys were designed to produce a national
picture of noise exposure and of attitudes to noise. The clustered design of
the samples means that there are large portions of Greater London where
no interviews or measurements took place. Whilst the national sampling
strategy has produced good estimates of population exposure and
attitudes over the whole country, the sample design will result in higher
uncertainties in Greater London than might otherwise be expected.