UK-wide support infrastructure for low frequency noise sufferers ('LFN Network')

Moorhouse, AT; Baguley, D; Husband, T

Abstract

The project was set up to meet a need for improved treatment of Low Frequency Noise (LFN) complaints in cases where no noise source could be found. Such cases can be highly distressing for the complainant and difficult to handle by the Environmental Health Officers (EHOs) concerned and so tend to result in disproportionate use of resources. The hypothesis is that, irrespective of the (unknown) cause of the LFN perception, the perception may be lessened through application of techniques specifically adapted from the field of tinnitus and hyperacusis therapy. The aim of the project was therefore to establish, on a trial basis, a national network of treatment centres for sufferers of LFN located within the existing network of tinnitus clinics in the UK.


A network of nine audiology centres was established, including eight with a good geographical spread in England and one in Scotland. A treatment protocol, specific to LFN cases, was then developed through discussions with the centres and a referral pathway was also established. Each centre made contact initially with EHOs in one or two local authorities in their vicinity to offer the service which was widened to a larger catchment area if sufficient referrals were not forthcoming.


Fourteen subjects took part, eleven of which were referred from EHOs, the remaining three being self-referred. Outcome measures were based on a combination of validated questionnaires for general health, anxiety, depression, tinnitus handicap (with LFN substituted for tinnitus) and hyperacusis, combined with visual-analogue scales specifically developed for LFN to measure the pitch and loudness of the perceived LFN and the associated distress. Qualitative and open questions were also used.


Potential benefits to EHOs of being able to make referrals were evaluated by semi-structured telephone interviews in which five EHOs participated. Generally, EHOs were very positive about the service and wanted it to continue. It was clear that LFN cases require significant resources which can be reduced if the referral service is available. Audiologists’ experience was evaluated in a similar way: they were generally willing to take part in the scheme and wanted it to continue and there was a feeling that they would have liked more referrals to get more experience in the use of the protocol.


The results showed a mixed picture with some clients, three in particular, showing improved scores across a range of measures with little or no benefit for others and a worsening for one case. The improvement of some clients is positive given the lack of options available for this client group, however, the success of the approach can be considered partial at best.


The questionnaire scores indicated that individuals taking part were significantly agitated, stressed and distressed. Those individuals with LFN complaint have a significant clinical need although in the main they were not clinically anxious or depressed.


The model proposed of stress and increased auditory gain is a plausible explanation for the symptoms noted in LFN cases. In particular, the involvement of the sympathetic autonomic nervous system, and of the emotional brain, is likely to be a faithful representation of the clinical situation.


A number of useful signposts for future development were derived. First, EHOs as well as audiologists should ideally receive training in best practice to help them to handle the particular sensitivities of LFN cases. More awareness and information for GPs is also recommended. A simplification of the referral route, potentially going direct to the audiologist rather than via the GP would also be beneficial.


A strong argument for the continuation of the service is that some EHOs are now taking the initiative in contacting audiologists independently to refer LFN complainants in ‘No Noise Found’ cases. Without adequate training things could be made worse but access to a specific LFN protocol and associated training is likely to increase the chances of success significantly. It is recommended that existing guidance for EHOs be extended to include details of audiology services, guidelines for EHOs in making referrals and reference to the LFN treatment protocol.

Using data from the study two independent estimates of the incidence rates of LFN cases can be derived. It is estimated that there are up to 160 complainants per year in the NHS corresponding to 0.32 cases per 100 thousand per year. The incidence rate based on referrals made by EHOs is 1.01 per 100 thousand per year within local authorities. It is not known to what extent, if any, these populations overlap.

Citation

Moorhouse, A., Baguley, D., & Husband, T. (2011). UK-wide support infrastructure for low frequency noise sufferers ('LFN Network')

• Report Type: Project Report
• Publication Date: Mar 11, 2011
• Deposit Date: May 3, 2019
• Publicly Available Date: May 3, 2019
• Publisher URL: http://randd.defra.gov.uk/Default.aspx?Menu=Menu&Module=More&Location=None&Completed=0&ProjectID=16125#RelatedDocuments
• Additional Information: Access Information : This report is available under Open Government Licence; Funders : Defra; Projects : Investigation into the potential for a UK-wide Support Infrastructure for Low Frequency Noise Sufferers - NO0206; Grant Number: NANR271