Construction noise database (phase 3): Evaluation of established measurement protocol

Executive Summary 1.1 The established method for obtaining noise emission data for the update of a database of noise from construction plant is examined. 1.2 The established measurement protocol involves the collection of plant noise measurements using a sound level meter, and the normalisation of the data to 10m. 1.3 The results of analytical and experimental investigations conclude that this measurement protocol is reasonably accurate and a practical method for the characterisation of plant sound power on-site for both stationary and dynamic activities

Living with helicopter noise : evaluating sound insulation techniques for domestic dwellings using real helicopters

Specific remedial works designed to improve sound installation and reduce the noise level produced by helicopters inside dwellings are described. The theoretical problems and practical solutions to installing high performance acoustic insulation to a traditional property in the UK are presented. A novel application of ISO 140-5 is presented using real helicopters to measure sound insulation in-situ in the presence of multiple flanking transmission paths. Dedicated field trials to evaluate the performance of such acoustic double-glazing and associated modifications systems were performed and the precautions taken to minimise measurement uncertainties over the extended time period of the trials are detailed. The field trials involved the use of military training helicopters following selected flight paths around the property while noise level measurements were made internally and externally, before and after replacement of the existing single glazed windows and attenuated ventilation units were installed. The results show that after replacing the main windows with acoustic insulated glazing units, insulation levels of 40dB or above are achieved in most rooms. The results also illustrate the importance of effectively addressing ventilation when windows are replaced. It is concluded that despite complications due to sound flanking and regulatory ventilation, the use of acoustic double-glazing units and properly attenuated ventilation units can effectively reduce helicopter noise in suitable dwellings

A procedure for the assessment of low frequency noise complaints

The development and application of a procedure for the assessment of low frequency noise (LFN) complaints are described. The development of the assessment method included laboratory tests addressing low frequency hearing threshold and the effect on acceptability of fluctuation, and field measurements complemented with interview-based questionnaires. Environmental health departments then conducted a series of six trials with genuine "live" LFN complaints to test the workability and usefulness of the procedure. The procedure includes guidance notes and a pro-forma report with step-by-step instructions. It does not provide a prescriptive indicator of nuisance but rather gives a systematic procedure to help environmental health practitioners to form their own opinion. Examples of field measurements and application of the procedure are presented. The procedure and examples are likely to be of particular interest to environmental health practitioners involved in the assessment of LFN complaints

Annoyance due to railway vibration at different times of the day

The time of day when vibration occurs is considered as a factor influencing the human response to vibration. The aim of the present paper is to identify the times of day during which railway vibration causes the greatest annoyance, to measure the differences between annoyance responses for different time periods and to obtain estimates of the time of day penalties. This was achieved using data from case studies comprised of face-to-face interviews and internal vibration measurements (N=755). Results indicate that vibration annoyance differs with time of day and that separate time of day weights can be applied when considering exposure–response relationships from railway vibration in residential environments

Human response to vibration in residential environments (NANR209), technical report 2: measurement of response

Based on a review of the literature and the best practice guidance available, a social survey questionnaire was developed to measure residents’ self-reported annoyance and to provide data suitable for establishing exposure-response relationships between levels of annoyance and levels of vibration. The development of the questionnaire was influenced by a number of previous studies such as: the social survey questionnaire developed for the NANR172 Pilot Study of this research (Defra, 2007); best practice guidelines for the development of socio-acoustic surveys issued by ICBEN and presented in the current International Standard (Fields et al., 2001; ISO/TS 15666:2003); the Nordtest Method (2001) for the development of socio-vibration surveys, and a peer review of the social survey questionnaire by international experts in the field. In order to avoid influencing responses and reasons for participation in the research, the survey was introduced as a survey of neighbourhood satisfaction. The questionnaire design, through the use of sections, enables new sections to be added to the questionnaire so that specific vibration sources can be investigated in more depth. In addressing the ‘response’ component in the ‘exposure-response’ relationship, the questionnaire was designed to yield interval-level measurement data suitable for analysis with vibration measurement data via two response scales: the five-point semantic and the eleven-point numerical scales. This decision was largely founded upon the ability of the two scales to meet the criteria established by ICBEN (Fields et al., 2001) for socio-acoustic survey design. Detailed procedures were documented, following the field trial of the questionnaire, in terms of the role of the interviewer, the recording of information and the transfer of the data to the relevant database for subsequent analysis and to inform the vibration team responsible for the ‘exposure’ component of this research project