Merseyside Noise Study :: Methods and background

Methods & Background

Some information about public attitudes to noise was available at a national level, but there was very little evidence available at a Merseyside level about how widespread or significant any problems with environmental noise were. As well as contributing to the increasing requirement at a European and UK level for managing environmental noise, the Merseyside Noise Study was also developed with particular emphasis on the importance of transport related noise and potential effects on people’s health.

It was very important that the results of the Merseyside Noise Study were representative, robust and statistically valid. For this reason, a lot of effort was spent at the start of the project on developing and agreeing appropriate methods for the different parts of the study, especially the public perception survey and the noise monitoring.

As part of the study, a workshop meeting was held with noise specialists from each of the Merseyside local authorities and other interested parties to agree the methods that would be used in the study.

Details of the study methods are available in the Stage 1 report. The desk study and literature review relating to environmental noise and its effects carried out for the study is provided in the Stage 2 report.

Merseyside Noise Study Stage 1 Report (67 KB)

Merseyside Noise Study Stage 1 Report Appendix(231 KB)

Merseyside Noise Study Stage 2 Report (139 KB)

What is ambient noise ?

Ambient noise is often referred to as environmental noise. It is the noise that we hear in day to day life and does not include workplace noise. The Merseyside Noise Study concentrated on the noise that people hear when in and about their homes. This is generally made up of noise from transportation, commercial activities and the sounds made by neighbours and other people.

Why is environmental noise important?

Noise is one of the most widespread pollutants in the United Kingdom. Environmental health departments across the UK receive over 300,000 complaints every year about noise. Most, if not all, residential properties in urban areas are affected by at least one type of environmental noise. New legislation originating from the EU requires the assessment of environmental noise and the production of Noise Action Plans for large urban areas.

Why was the Merseyside Noise Study carried out ?

Some work has been carried out at the national level to assess attitudes to noise and to measure environmental noise levels. However, these studies provided little information about attitudes to noise and actual levels on Merseyside. It was therefore felt that there was a need to find out a lot more about environmental noise on Merseyside.

The overall aim of the study was to determine the extent to which people on Merseyside think noise is a problem and to identify which types of noise and noise sources have the greatest effect on people, with specific reference to transport sources. The longer term aim is to develop a Merseyside Environmental Noise Strategy and a Noise Action Plan.

What did the Merseyside Noise Study involve ?

The study covered the whole area of Merseyside, including all five council areas, Liverpool, Knowsley, Sefton, St Helens and Wirral. All the different areas of Merseyside were included so that the effects of environmental noise in different situations, e.g. town and city centres, residential suburbs and the more rural areas, could be assessed.

The study included a survey of public attitudes, which questioned 1,170 residents across Merseyside (10 people in each of the Merseyside electoral wards). A questionnaire was designed to assess the different types of noise that residents hear, whether the noise caused bother or annoyance, and how noise compared with other pollutants and factors affecting quality of life. In addition, noise measurements were carried out over 24 hours at 90 different locations across Merseyside (18 in each local authority area). The study paid particular attention to transport-related noise.

The findings of the Merseyside Noise Study were presented at a seminar on the 22nd June 2004 at the Merseyside Maritime Museum.

Public perception survey methods

The method for the public perception survey was designed to meet the following requirements:

Be representative of the whole of Merseyside, in terms of geography and population
Provide data that were comparable with any national surveys, to enable the situation in Merseyside to be understood in a wider context (e.g. National Noise Attitude Survey)
Capture attitudes to transport noise in particular

It was agreed that face to face interviews were the best method and a questionnaire was designed for use in the interviews. It was based on the questionnaire used in the National Noise Attitude Survey, but with some amendments specific to the Merseyside Study.

Details of the survey methods adopted are available in the Noise Study Stage 1 report.

Noise monitoring and modelling methods

The noise monitoring methodology was chosen to provide data compatible with that used in the National Noise Incidence Survey.

Noise monitoring was carried out at 90 different locations over a continuous 24 hour period on a weekday with the microphone at a height of 1.2m above ground level and 1m from the façade of a building wherever possible.

Noise measurements were carried out during relatively calm and dry weather conditions. The aim was to ensure that local wind speeds did not exceed 5m/s during the survey, and that there was no heavy rain during the period. Measurements were repeated where the above conditions were not met. Noise measurements were not carried out during school holidays.

The noise modelling has used the 'Lima' noise prediction software. This software is used to map noise levels in large urban areas, and has already been used to map Birmingham and Westminster within the UK. The software produces noise contours from a three-dimensional model of the noise source and surrounding buildings and ground contours. The results demonstrate the spread of noise in urban areas. The areas that have been noise mapped using the model are each approximately 1 km2.

Details of the monitoring and modelling methods adopted are available in the Noise Study Stage 1 report.