This publication (excluding the logo) may be reproduced free of charge in any format or medium provided that it is reproduced accurately and not used in a misleading context. The material must be acknowledged as Crown copyright with the title and source of the publication specified.

/pdf/a-review-of-published-research-on-low-frequency-noise-and-1ohbz9hvvn.pdf

A Review of Published Research on Low Frequency Noise and its Effects

SUMMARY The aim of this study is to recommend a method for assessing low frequency noise (LFN), suitable for use by Environmental Health Officers (EHOs) in the UK. A general introduction to LFN is given, in which it is argued that a method of assessment is needed both from the sufferer's point of view, because there is currently not much to protect them against LFN, and from the Environmental Health Officer's point of view, where guidance is needed in determining whether a nuisance exists. Criteria already in use in Germany, Sweden, Denmark, the Netherlands and Poland were reviewed and compared. Experience from these countries in applying the criteria was also reviewed, and was found to be generally positive. A complementary set of field and laboratory studies was conducted in order to establish the best form for an assessment method. In the field studies, eleven cases of reported LFN were investigated, as well as five control cases where no complaints about LFN had been received. Analysis of recordings made over three to five days at each location distinguished three groupings: positively identified LFN, unidentified, and marginal. Three cases were positively identified, meaning that the various national criteria were exceeded and there was correlation between the resident's logged comments and the LFN level. Five cases were unidentified: the criteria were generally not exceeded, (except perhaps by traffic noise), and there was a lack of correlation between comments and noise levels. Three cases were marginal in that the LFN was marginal with respect to the criteria and did not correlate with comments. It was concluded that the criteria were successful at distinguishing cases where an engineering solution could be applied from those where no such solution could be found. In the laboratory tests, a set of 'thresholds of acceptability' were established by asking 18 subjects to set the level of various low frequency sounds to a just-acceptable level for imagined day and night situations. The sounds presented consisted of a set of tones across the low frequency range, 'real' LFN extracted from field test recordings, and synthesised beating tones with varying degrees of fluctuation. LFN sufferers were found to be the least sensitive group in absolute terms, contrary to the common image of ultra-sensitive individuals. In relative terms however, they were the most sensitive group in that they set acceptability thresholds closer to their threshold of hearing. From the existing national reference curves, …

/pdf/proposed-criteria-for-the-assessment-of-low-frequency-noise-cjezlk3kgh.pdf

Proposed criteria for the assessment of low frequency noise disturbance

From 203 cases of low-frequency complaints a random selection of twenty-one cases were investigated. The main aim was to answer the question whether the annoyance is caused by an external physical sound or by a perceived but physically non-existing sound, i.e. low-frequency tinnitus. Noise recordings were made in the homes of the complainants, and the complainants were exposed to these in blind test listening experiments. Furthermore, the low-frequency hearing function of the complainants was investigated, and characteristics of the annoying sound were matched. The results showed that some of the complainants are annoyed by a physical sound (20-180 Hz), while others suffer from low-frequency tinnitus (perceived frequency 40-100 Hz). Physical sound at frequencies below 20 Hz (infrasound) is not responsible for the annoyance or at all audible - in any of the investigated cases, and none of the complainants has extraordinary hearing sensitivity at low frequencies. For comparable cases of low-frequency noise ...

/pdf/a-detailed-study-of-low-frequency-noise-complaints-3l1jnnjx70.pdf

A Detailed Study of Low-Frequency Noise Complaints

This paper summarizes the presently available knowledge about the association between low-frequency noise and its effects on health. A database was constructed with a total of 142 articles published between 2016 and 2019 regarding low-frequency noise exposure and its effects on health. A total of 39 articles were analysed in depth. The articles were divided into categories according to the effects on human health addressed. Regarding the emitting source, there was a greater number of articles addressing issues related to sources of environmental noise and noise from wind turbines. As for the effects generated on human health, there was a greater number of articles referring to the effects on sleep disorders, discomfort, sensitivity to and irritability from noise, annoyance, hearing loss, and cardiovascular diseases, and these effects are analysed in more detail in the present article.

/pdf/low-frequency-noise-and-its-main-effects-on-human-health-a-1mi8gdwyfc.pdf

Low-Frequency Noise and Its Main Effects on Human Health—A Review of the Literature between 2016 and 2019

This paper describes a case study in which low frequency noise was suspected of causing disturbance in a semi-rural location close to an industrial estate. Previous attempts using conventional acoustic measurement techniques to resolve the case, or even prove the existence of a real acoustic problem, had proved unsuccessful. In the present study, the authors applied a novel integrated acoustic/microseismic measurement system, and assessed the resultant data using criteria from the German national standard DIN 45680. Using this approach, the authors successfully resolved the low frequency noise problem and, after a test involving a sequential shutdown at a suspect industrial site, established the precise cause of the disturbance. The paper thus supports the criteria in DIN 45680 as a predictor of annoyance due to low frequency noise and as an aid in resolving such problems. It also illustrates the flexibility of the combined acoustic/microseismic technique and the advantages of the method over conventional...

https://journals.sagepub.com/doi/pdf/10.1260/026309202321834636

A Case Study of Low Frequency Noise Assessed Using DIN 45680 Criteria

It is proposed that low frequency noise/vibration problems are best tackled by a combination of acoustic and microseismic methods, rather than using each method in isolation. A new integrated method was devised and it was demonstrated that ‘ the whole is greater than the sum of the parts’ . The benefits and versatility of the new method are illustrated with reference to a case study. Unmanned monitoring took place at several houses near to an industrial site, using a multi-channel recording technique. Comparison of various components of the sound and vibration fields in each house was then carried out, which allowed various propagation paths to be distinguished. A range of further signal processing analyses was also employed to aid source determination.

An Integrated Acoustic/Microseismic Approach to Monitoring Low Frequency Noise & Vibration — A Case Study

Environmental lore frequency noise and vibration (or hum) is a growing annoyance and potential health hazard to many people, according to surveys conducted by the UK's Low Frequency Noise Sufferer's Association. This paper describes attempts to measure the hum using microseismic methods. Sensitive three-component seismometers and high resolution digital dataloggers were employed in the homes of hum sufferers, and three-dimensional vibrational data were recorded overnight. Frequency analyses were then performed on the time series data using Fast Fourier Transform methods. In one case study, a clear signal was observed corresponding to a fundamental vibrational frequency peak of 10 Hz. At least one harmonic frequency peak (30 Hz) was also apparent. It is suggested that local industry of some kind (with machinery running overnight at an operating frequency of 10 Hz) may he responsible for this ground-borne disturbance. In another house occupied by hum sufferers, no notable ground velocities were recorded overnight with the seismometer mounted on ground floor concrete foundations, Significant levels of vibration were only observed in an upstairs bedroom, by placing the instrument on floorboards which appear to be excited by acoustic waves in the room. It is inferred that in this case the hum is predominantly air-borne; again, local industry is a likely source. Low frequency hum, both acoustic and ground-borne, is a very real problem which causes sufferers great distress. It is possible to measure the hum and determine its frequency characteristics using microseismic techniques. Urgent revision of current legislation is needed to limit industrial output levels of low frequency noise/vibration, especially at night time.

https://journals.sagepub.com/doi/pdf/10.1177/026309239901800302

Ian Rushforth

Papers

A Case Study of Low Frequency Noise Assessed Using DIN 45680 Criteria

An Integrated Acoustic/Microseismic Approach to Monitoring Low Frequency Noise & Vibration — A Case Study

Microseismic investigations of low frequency vibrations and their possible effects on populations