David Welch

Dr. David Welch

Audiology Section, School of Population Health, University of Auckland, 2011 Auckland, New Zealand

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
DSDaniel Shepherd
Daniel Shepherd
DWDavid Welch
David Welch
Kim DirksKim Dirks
Kim Dirks
RMRenata Mathews
Renata Mathews
The relationship between environmental noise and health is poorly understood but of fundamental importance to public health. This study estimated the relationship between noise sensitivity, noise annoyance and health-related quality of life in a sample of adults residing close to the Auckland International Airport, New Zealand. A small sample (n = 105) completed surveys measuring noise sensitivity, noise annoyance, and quality of life. Noise sensitivity was associated with health-related quality of life; annoyance and sleep disturbance mediated the effects of noise sensitivity on health.

DSDaniel Shepherd
Daniel Shepherd
DWDavid Welch
David Welch
Kim DirksKim Dirks
Kim Dirks
David McbrideDavid Mcbride
David Mcbride
People typically choose to live in quiet areas in order to safeguard their health and wellbeing. However, the benefits of living in quiet areas are relatively understudied compared to the burdens associated with living in noisy areas. Additionally, research is increasingly focusing on the relationship between the human response to noise and measures of health and wellbeing, complementing traditional dose-response approaches, and further elucidating the impact of noise and health by incorporating human factors as mediators and moderators. To further explore the benefits of living in quiet areas, we compared the results of health-related quality of life (HRQOL) questionnaire datasets collected from households in localities differentiated by their soundscapes and population density: noisy city, quiet city, quiet rural, and noisy rural. The dose-response relationships between noise annoyance and HRQOL measures indicated an inverse relationship between the two. Additionally, quiet areas were found to have higher mean HRQOL domain scores than noisy areas. This research further supports the protection of quiet locales and ongoing noise abatement in noisy areas.

1 January 2013 in Noise and Health
Verified
Journal Article
Open access
PDF file
DWDavid Welch
David Welch
DSDaniel Shepherd
Daniel Shepherd
Kim DirksKim Dirks
Kim Dirks
David McbrideDavid Mcbride
David Mcbride
SMSamantha Marsh
Samantha Marsh
Evidence is emerging linking environmental noise to health problems. Noise can affect health directly and indirectly: For example, noise sensitivity moderates the effects of noise annoyance, which in turn mediates the effects of noise exposure. An alternative hypothesis is that noise sensitivity marks the presence of susceptibility to health problems in general, including annoyance from noise. Whether noise sensitivity causes poor health or whether it is a marker of susceptibility to health problems was addressed by comparing the results of a community-based survey of people with similar noise sensitivity profiles but different environmental noise exposures. A questionnaire was delivered to people living in two socio-economically-matched areas: One was within 50 m of a motorway and the other was away from any significant source of environmental noise. The questionnaire contained 58 questions comprised of the World Health Organization health-related quality of life questionnaire (WHOQOL), and questions about amenity, neighborhood issues, environmental annoyances, demographics, and noise sensitivity. Noise sensitivity did not vary with proximity to the motorway but annoyance with traffic noise and fumes was greater in those living close to the motorway than in those who were not. Scores on the four WHOQOL domains (physical, psychological, social, and environmental) were lower in those living close to the motorway, and the WHOQOL domain scores correlated negatively with noise sensitivity in those who lived near motorways but not in those who lived in the quieter areas. This suggests that noise sensitivity is related to poor health outcomes rather than being a trait marker of susceptibility to health problems in general.

26 April 2023 in Transport Reviews
Verified
Journal Article
Open access
DWDavid Welch
David Welch
DSDaniel Shepherd
Daniel Shepherd
Kim DirksKim Dirks
Kim Dirks
RRRavi Reddy
Ravi Reddy
The relationship between transport noise and health outcomes is complex, in part because of the large number of factors involved as well as the range of health impacts, both direct and indirect. To enable the reader to come to grips with the complexity, we have divided the health outcomes into groups: those that are more directly linked to transport noise exposure and those that are more indirectly linked. Four health outcomes, namely annoyance, cognitive disruption, sleep problems, and noise-induced hearing loss, can be directly attributable to transport noise exposure. Less direct outcomes are stress, mental health, metabolic health, cardiovascular health, and overall health-related quality of life. Stress may occur as a direct response to noise, or may occur in response to the aforementioned direct effects. The stress response is a survival mechanism in the short term, but in the long term, stress may lead to systemic health conditions, namely metabolic and cardiovascular outcomes, and to mental health conditions. Finally, a global health outcome that incorporates all of the more direct outcomes is health-related quality of life. Other exposures associated with transport noise that may explain parts of the health outcomes need to be acknowledged, including exposure to social inequities, air pollution, and vibration. These may all be more likely to be experienced by people who are exposed to transport noise in the community and may thus influence the outcomes. Finally, transport noise appears to have more impact on health in those who are noise sensitive, thus noise sensitivity is a key moderator of all the effects observed.

DSDaniel Shepherd
Daniel Shepherd
Kim DirksKim Dirks
Kim Dirks
DWDavid Welch
David Welch
David McbrideDavid Mcbride
David Mcbride
JLJason Landon
Jason Landon
Air pollution originating from road traffic is a known risk factor of respiratory and cardiovascular disease (both in terms of chronic and acute effects). While adverse effects on cardiovascular health have also been linked with noise (after controlling for air pollution), noise exposure has been commonly linked to sleep impairment and negative emotional reactions. Health is multi-faceted, both conceptually and operationally; Health-Related Quality of Life (HRQOL) is one of many measures capable of probing health. In this study, we examine pre-collected data from postal surveys probing HRQOL obtained from a variety of urban, suburban, and rural contexts across the North Island of New Zealand. Analyses focus on the covariance between air pollution annoyance and noise annoyances, and their independent and combined effects on HRQOL. Results indicate that the highest ratings of air pollution annoyance and noise annoyances were for residents living close to the motorway, while the lowest were for rural residents. Most of the city samples indicated no significant difference between air pollution- and noise-annoyance ratings, and of all of the correlations between air pollution- and noise-annoyance, the highest were found in the city samples. These findings suggest that annoyance is driven by exposure to environmental factors and not personality characteristics. Analysis of HRQOL indicated that air pollution annoyance predicts greater variability in the physical HRQOL domain while noise annoyance predicts greater variability in the psychological, social and environmental domains. The lack of an interaction effect between air pollution annoyance and noise annoyance suggests that air pollution and noise impact on health independently. These results echo those obtained from objective measures of health and suggest that mitigation of traffic effects should address both air and noise pollution.

DWDavid Welch
David Welch
GFGuy Fremaux
Guy Fremaux
Many people choose to expose themselves to potentially dangerous sounds such as loud music, either via speakers, personal audio systems, or at clubs. The Conditioning, Adaptation and Acculturation to Loud Music (CAALM) Model has proposed a theoretical basis for this behaviour. To compare the model to data, we interviewed a group of people who were either regular nightclub-goers or who controlled the sound levels in nightclubs (bar managers, musicians, DJs, and sound engineers) about loud sound. Results showed four main themes relating to the enjoyment of loud sound: arousal/excitement, facilitation of socialisation, masking of both external sound and unwanted thoughts, and an emphasis and enhancement of personal identity. Furthermore, an interesting incidental finding was that sound levels appeared to increase gradually over the course of the evening until they plateaued at approximately 97 dBA Leq around midnight. Consideration of the data generated by the analysis revealed a complex of influential factors that support people in wanting exposure to loud sound. Findings were considered in terms of the CAALM Model and could be explained in terms of its principles. From a health promotion perspective, the Social Ecological Model was applied to consider how the themes identified might influence behaviour. They were shown to influence people on multiple levels, providing a powerful system which health promotion approaches struggle to address.