Aviation night noise effects (ANNE) study FAQs

This research study is about the impact of aviation noise at night on sleep and annoyance. The study is seeking to answer the following research question: What is the relationship between exposure to night-time aviation noise and sleep disturbance and annoyance, and how does this relationship vary by different times of night?

The research will run in 2 phases. Phase One is a large-scale cross-sectional survey carried out among residents living near eight UK airports to assess associations of aircraft noise exposure at night and subjective sleep disturbance and annoyance. Phase Two is an observational study where physiological assessments of (objective) sleep disturbance will be linked to aircraft noise exposure at the participant’s home. Phase Two will recruit a sub-set of Phase One survey participants.

The Department for Transport’s (DfT) Transport Analysis Guidance (TAG) provides appraisal values that can be used to understand the impact that exposure to aviation noise has on annoyance, risk of acute myocardial infarction (AMI), stroke, dementia and sleep disturbance [1]. However, this uses exposure-response functions that are not specific to night-time aviation noise. Recent literature suggests the impacts of exposure to aviation noise during the night-time can differ to that experienced during the day.

Exposure to aviation noise at night can impact on physical and mental well-being [2]. Humans continue to respond to sounds in the environment even when asleep, which can cause awakenings and poor sleep quality [3, 4]. This sleep disturbance can have a negative impact on health, increasing the risk of daytime sleepiness, hypertension, and cardiovascular disease [5].

The DfT recognises this evidence gap and is undertaking this research to derive exposure-response functions between night-time aviation noise metrics and sleep and annoyance outcomes. This could be used to support the ongoing reviewing of night-time aviation policy, to inform the DfT’s future policies for night-time aviation noise exposure and assist with the management and mitigation of health impacts on local communities.

The Department for Transport (DfT) recognises this is an evidence gap that needs to be filled in order to support important policy decisions on aviation noise. The DfT has therefore taken on the responsibility of undertaking this multi-year research project and is fully funding the project.

Phase One: Fieldwork associated with Phase One of the project has now been completed. Addresses were chosen at random to make sure that the study achieved a truly representative selection of households. This ensured that every address had an equal chance of being selected and there was no bias in terms of how the sample of survey participants were selected. The addresses that were chosen received a letter in the post inviting up to two adults in their household to take part in the research. It was not possible for addresses to be replaced by anyone else because this would have biased the results. Only those who were invited were able to participate and complete the survey.

Phase Two: Participants who took part in Phase One were asked if they wanted to be contacted about potentially participating in Phase Two of the research project at the end of the survey. Participants who consented to being contacted about Phase Two are being invited to participate in the study by the research team at St George’s, University of London throughout 2024 and into early 2025. Participants are being invited via email, phone or letter depending on the contact details they shared in the survey. The order in which participants are being invited is random. In this phase, we first contact one adult per household to participate. If two adults in a household have consented to being contacted, one will be selected at random first. If required in order to meet required sample sizes for the Study, the second adult in the household may be contacted to participate.

Phase One: Those who were invited and fully completed the survey received a £10 Love2Shop voucher which can be redeemed at a range of high street shops. It was received either via email or in the post, depending on each participant’s choice. Participants needed to complete the survey in its entirety to be eligible to receive the voucher.

Phase Two: Those who complete the sleep study will receive a Love2Shop voucher worth up to £200. The amount will depend on the completeness of data collected by the participant.

Phase One: If you completed the survey and have changed your mind about participating it is no longer possible to request to have your data deleted. This was possible up to two weeks after completing the survey, when the data could still be linked to your personal information. This time period has now elapsed, and we will be unable to withdraw your data from the study.

Phase Two: You have the right to change your mind and withdraw at any time during the study without giving a reason. We can remove your data from the study whilst it is still possible to link this to your personal information. This will be up to two weeks after you ship the study equipment back to us. After this time period, any sleep and noise data that is no longer linked to your personal data will not be able to be identified to be deleted and therefore we will be unable to withdraw your data from the study.
If you do wish to withdraw your permission to use your information you can contact the Principal Investigator Charlotte Clark by email at annestudy@sgul.ac.uk.

The project team has a wide range of experience to draw on in order to answer the research question. The study has been designed in two phases:

• Phase One is a large-scale cross-sectional survey carried out among residents living near eight UK airports to assess associations of aircraft noise exposure at night and subjective sleep disturbance and annoyance.
• Phase Two will recruit a sub-sample from the cross-sectional survey into an objective sleep disturbance study, where physiological assessments of (objective) sleep disturbance will be linked to aircraft noise exposure at the participant’s home. The question of differences in impacts of aviation noise on sleep disturbance at different times of the night can be addressed using measures of objective sleep disturbance where aviation noise during specific time-periods can be linked to objective physiological reactions (e.g., awakenings).

The cross-sectional survey (Phase One) asked respondents to think about the “summer” period (defined as mid-June to mid-September 2022). Aircraft noise exposure levels were modelled at each address where a survey was completed. The models are computerised versions of the airport operations that occurred over the summer period. They are used to calculate the level of noise from the operations. A model for each airport was included in the study. Validation work of the model was undertaken for each airport utilising LAmax and SEL (Sound Exposure Level) event levels captured from each airport’s noise monitoring terminals. This was to ensure that the noise model broadly reflects measured noise levels.

Fieldwork for the survey took place over 9 weeks from October 2022 to January 2023. The survey used established and standardised questions, where available, with questions selected to align with those used in SoNA 2014 (Survey of Noise Attitudes), previous UK national noise surveys and the FAA's (Federal Aviation Authority, USA) National Sleep Study to ensure continuity and comparability, where possible. The objective sleep disturbance study (Phase Two) is currently recruiting study participants.

Yes, a pilot study of the cross-sectional survey was conducted in July 2022 to test the research approach. The overall aims of the pilot study were to test the survey procedures and questions. Acceptability of the objective sleep study was also tested through the use of a consent question in the cross-sectional subjective survey.

A feasibility study of the objective sleep study was then conducted in Spring 2023. A sub-sample of 21 participants from the cross-sectional survey were recruited to test the study methodology and analysis, ahead of the main objective study.

Push-to-web methodology involves writing to a random sample of addresses and asking the residents to take part in an online survey by typing the survey URL into their address browser. They also receive a unique access code to enter the online survey. This methodology is increasingly used on social surveys [6] (for example, the Census 2021 was conducted as push-to-web first for the majority of households) and enables a large sample to be reached, whilst minimising costs in comparison to surveys conducted by field interviewers face-to-face.

Achieving the highest possible response rate is very important in order to maintain data quality, reduce non-response bias, and ensure that the sample is as representative as possible. We employed a number of strategies to encourage people from the selected addresses to take part in the research when recruited at Phase One, including:

• Keeping the survey open for 6 weeks to allow enough time to participate
• Offering an incentive for taking part
• Ensuring the survey is straightforward to complete and not too long
• Creating engaging communication materials
• Spacing out communication appropriately:
  • After one week of no response, a reminder letter was sent
  • After three weeks of no response, a second reminder letter that also contained a paper questionnaire and pre-paid return envelope. This enabled participants to complete on paper if they preferred this to the online method.

We want to ensure that the responding population is representative of the population exposed to night-time aviation noise around the selected airports. We want to make sure that we receive responses from a range of people, backgrounds and attitudes. We have tried to reduce bias by doing the following things:

• A stratified random [7] sample of addresses around each selected airport were chosen to ensure that a range of night-exposure experiences are included in the sample.  This means we have ensured the sample includes residents living in noise bands ranging from 35dB - >60dB.
• Inviting households to take part in a study about issues within their local environment and neighbourhood. Aviation noise was not explicitly mentioned in order to reduce non-response bias [8]. This approach was agreed to be the best balance of reducing non-response bias whilst maintaining relevance to the study content and follows a similar approach to previous noise surveys such as SoNA 2014.
• Up to two adults per household can take part in the online survey and participants can choose which two participate. This ensures that the last stage of sampling is still random.

The target population of this study is all residents living near Heathrow, Gatwick, Luton, Stansted, Manchester, East Midlands, Bristol and Glasgow airports that are exposed to night-time aviation noise. Using the postcode address file (PAF) [9], we have identified a list of all the addresses in the target population and linked these addresses to data on night-time aviation noise exposure level, socio-economic status of the area, exposure to night-time road and rail noise, and proportion of the population in an area belonging to Black and Minority Ethnic (BME) groups.

In order to characterise the relationship between night-time aviation noise exposure and outcomes such as annoyance and sleep disturbance, we have divided the target population into smaller strata based on their night-time aviation noise exposure.

Our aim is to survey a roughly equal number of respondents in each night-time aviation noise strata. We have drawn a stratified random sample of addresses within each strata and invited up to two people in each household to participate in the survey.

In order to ensure the sample is representative, prior to drawing the sample of addresses we sorted the target population within night-time aviation noise bands according to the stratification variables: airport, socio-economic status, exposure to night-time road and rail noise, and proportion of the population in an area belonging to Black and Minority Ethnic (BME) groups. We then selected a systematic sample (with a random start) [10] of addresses within each noise strata. The stratification ensures that we have sampled addresses with a wide range of characteristics. For instance, within each strata we have selected addresses around all eight airports; from areas with high, medium, and low levels of socio-economic status; from areas with high, medium, low and negligible amounts of night-time road and rail noise exposure, and addresses in areas with varying proportions of BME residents.

The night-aviation noise data used in sampling is 2022 Estimated Lnight Airport Noise Exposure Data. This data has been estimated using 2016 Lnight noise grids obtained from the Department for Environment, Food and Rural Affairs (Defra) and the Scottish Government as generated under their respective Environmental Noise Regulations. The noise exposure grids have been adjusted by the Civil Aviation Authority to account for changes in the number of night-time aircraft movements between 2016 and forecast for 2022. The lowest continuous noise contour value reported differs by airport. Below the reported lowest noise contour value, we applied an approximation using overflight data to identify addresses around each airport exposed between 35 dB Lnight and the lowest reported noise contour.

We classified all commercial airports in the UK according to the number and timing of night-time aviation movements, approximate number of residents exposed to night-time aviation noise, geographic location, urban/rural status of communities exposed to night-time aviation noise, and presence and timing of restrictions on night-time flights. Airports without night-time flights were excluded.

From this list, we purposively selected eight airports to include those with a wide range of characteristics. These are Heathrow, Gatwick, Luton, Stansted, Manchester, East Midlands, Bristol and Glasgow airports.

There are a few reasons why we did not include more airports in this study, in the context of fixed time and resource constraints. First, a considerable amount of time and resources go into preparing the sample frame and exposure data for analysis around each airport. Second, given a fixed number of overall responses to the survey, we wanted to ensure robust numbers of respondents around each airport.

There was not an airport in Wales that met the criteria of the study due to night-time noise exposure being low around airports in Wales. Belfast City Airport does not have night-time flights, and therefore did not meet the criteria. We did consider Belfast International, but ultimately chose other airports because of the relatively small population exposed to night-time aviation noise around this airport.

For Phase One, data was collected through an online survey. Those who didn’t want to complete the survey online could take part by completing it on paper instead. Those who consent to being contacted about the objective sleep study and take part, will record their sleep using a Bittium Faros 180 device and sound in their home using a Svantek Sound Level Meter for seven nights.

We take great care to protect the confidentiality of the information people give us. NatCen, St George’s, and DfT will handle all data in accordance with the UK General Data Protection Regulation (UK GDPR).

NatCen, St George’s, and DfT will store data in line with ISO27001, ISO 20252 and Cyber Essentials Plus certification. Only staff working on the study will have access to your information and their access will be removed when no longer required.

For more information about how we deal with personal information from Phase One you can read the privacy notice here.

For more information about how we deal with personal information in Phase Two you can read the privacy notice here (PDF).

The sample frame for this study (i.e. the postcode address file (PAF)), is the most common sample frame of addresses used in surveys in the UK. It is used by many large-scale national surveys including the National Travel Survey, British Social Attitudes Survey, and the Annual Population Survey. It is common practice to select a stratified random sample of addresses to participate in PAF surveys to ensure that addresses from many different types of areas are included in the sample. We tested this approach in a pilot study around Manchester, Heathrow, East Midlands and Glasgow airports. The pilot study used a slightly different sample design to the mainstage so that response rates of addresses in different noise strata could be tested and oversampling of addresses in high noise areas could be used to inform the mainstage study sampling strategy.

The Survey of Noise Attitudes (SONA) 2014 was undertaken to understand people’s attitudes to noise from various sources, including from fixed-wing aircraft. SONA sampled participants based on their day-time aviation noise exposure, so whilst it asked a few questions relating to night-time aviation noise, there were limits to the conclusions that could be drawn relating to night-time aviation noise; this was a recognised limitation of SONA.

The Aviation Night Noise Effects (ANNE) study, being undertaken by the Department for Transport (DfT), is focussed on understanding the relationship between night-time aviation noise and sleep disturbance and annoyance. To do this, it samples participants based on their night-time aviation noise exposure. This means any findings from the study will be specific to the night-time period.

The Civil Aviation Authority (CAA) has been tasked with developing the new Aviation Noise Attitudes Survey (ANAS) as part of their new Noise Advisory Functions. ANAS is expected to build on lessons learnt from SONA and previous preparatory work undertaken by NatCen on behalf of the Independent Commission on Civil Aviation Noise (ICCAN) in 20216. Its focus will be to gather data about attitudes to aviation noise and the experience of exposure to day-time aviation noise. ANAS is currently ongoing. In contrast, the ANNE study's focus is to gather data about night-time effects on annoyance but also, the impacts exposure to aviation night-time noise has on sleep disturbance. In fact, ANNE will be the first study of aviation noise effects on sleep disturbance in the UK for 30 years.

This research study is following the recommendations that were given to the Independent Commission on Civil Aviation Noise by:

• selecting a range of noise exposure experiences, as detailed above
• selecting addresses exposed to the lowest levels, where possible
• using a purposive sampling method to select the airports included in the study
• ncluding key questionnaire content such as socio-demographic characteristics, standardised wellbeing measures and non-acoustic factors.

Phase One took place over 9 weeks from October 2022 to January 2023. Phase Two, which involves an observational study of a sub-set of participants from the first phase, will be in field over a calendar year from Spring 2024 to Spring 2025. Data processing and analysis will be undertaken after this time-period.

Fieldwork for Phase One was planned intentionally for the second half of 2022 to allow for the busy summer period to have just finished. The reason for this is twofold.

Firstly, it means participants would be completing questionnaires very shortly after a busy summer season of aviation activity; this maximises memory of the summer.

Secondly, it maximises the available sample as fewer people would be expected, for example, to be away on holiday.

The ANNE study is expected to conclude in 2025. The Department will consider undertaking a review of the research ahead of publication.

The research is expected to give evidence needed to derive exposure-response functions between night-time aviation noise metrics and sleep and annoyance outcomes, filling a recognised evidence gap. This could be used by the Department to support future review of night-time aviation policy, to inform future policies for night-time aviation noise exposure and assist with the management and mitigation of health impacts on local communities.

The research is also expected to support an update to the Department’s Transport Analysis Guidance (TAG), which provides appraisal values that can be used to understand the impact that exposure to aviation noise has on annoyance, risk of acute myocardial infarction (AMI), stroke, dementia and sleep disturbance. The research could update the Department’s TAG to provide appraisal values specific to night-time exposure.

Power calculations [12] have been used to inform our approach to balancing the study resources across the subjective survey and the objective sleep disturbance study. Both studies have been informed by power calculations, which demonstrate adequate power to detect effects of night-time aviation noise on the key outcomes of sleep disturbance (both studies) and annoyance (subjective survey). 

All data collected will be checked and reviewed and quality assurance checks will be undertaken on the analysis.

The Department has engaged on this research with communities through its Airspace and Noise Engagement Group (ANEG), as part of routine policy updates, and more specifically through the ANNE study Steering Group. For more information see question Do you have a Steering Group for the project, and if so, what is its membership? below.

It is best practice to not share specific details about the timing of the research until fieldwork has been undertaken. For this reason, the Department did not share specific timings of fieldwork with communities we surveyed in Phase One.

The Department plans to continue engaging with communities, including those we are surveying, through the ANNE study Steering Group. For more information see question Do you have a Steering Group for the project, and if so, what is its membership? below.

In order to support the sampling of participants for the study, suppliers and the Department engaged with those airports around which fieldwork was undertaken. This was necessary in order to explain to the airports what the study was seeking to do, and how, as well as secure the required data to support the design and development of the sampling strategy.

The Department also engaged on this research with airports through its Airspace and Noise Engagement Group (ANEG), as part of routine policy updates, and more specifically through the ANNE study Steering Group. For more information see question Do you have a Steering Group for the project, and if so, what is its membership? below.

It is best practice to not share specific details about the timing of the research until fieldwork has been undertaken. For this reason, the Department did not share specific timings of fieldwork with the airports we surveyed.

The Department plans to continue engaging with airports, including those we are surveying around, through the ANNE study Steering Group. For more information see question Do you have a Steering Group for the project, and if so, what is its membership? below.

The Civil Aviation Authority (CAA) has been tasked with developing the new Aviation Noise Attitudes Survey (ANAS) as part of their new Noise Advisory Functions. ANAS is expected to build on lessons learnt from SONA and previous preparatory work undertaken by NatCen on behalf of the Independent Commission on Civil Aviation Noise (ICCAN) in 20218. Whilst the full scope of ANAS is to be finalised, its focus will be understand attitudes to aviation noise and gather data about experience of exposure to day-time aviation noise. ANAS is currently ongoing. In contrast, the ANNE study's focus is to gather data about night-time effects on annoyance but also, the impacts exposure to aviation night-time noise has on sleep disturbance. In fact, ANNE will be the first study of aviation noise effects on sleep disturbance in the UK for 30 years.

A Steering Group for ANNE has been established and used to support project scoping, design and methodology development. Part of the Steering Group has also been used to support the reviewing of material e.g., results from the Pilot study. The Steering Group membership consists of Department for Transport (DfT) representatives, including representatives from the Department’s Transport appraisal and strategic modelling (TASM) team, and representatives from community groups (Aviation Environment Federation), industry (Sustainable Aviation), academia, The Civil Aviation Authority (The CAA), UK Health Security Agency (UKHSA) and the Department for Environment, Food and Rural Affairs (Defra).