The International Commission on Biological Effects of Noise (ICBEN), which meets every five years, reviewed the negative effects of noise on health at its ninth congress held earlier this year in Foxwoods, Conn.
International experts presented sessions on auditory and nonauditory effects of noise from transportation (automobiles, trains, or planes), personal listening devices, air pollution, and combined exposures. Results of studies on fatal work accidents related to noise, novel methodologies on assessing functional hearing capacity, and new developments in hearing protection were also presented.
Deanna Meinke and Brian Fligor focused on children's hearing. Fligor delivered evidence about the danger of personal listening devices and the risk of future hearing loss in young people, noting that potential hearing loss depends on earpiece type and fit. If the earpiece does not isolate from outside noise, users tend to increase volume to potentially risky levels in noisy environments. Meinke asserted that safe listening strategies are necessary for all potentially hazardous sources of loud sound, not just personal stereos. She emphasized that childhood noise exposures accumulate from a variety of sources (including social, sporting, and recreational activities) that should also be considered in determining the risks of noise-induced hearing loss and tinnitus.
William Martin's team on noise-induced hearing loss presented an interactive public education program titled "Dangerous Decibels." Thais Morata presented an ambitious European study showing interactions between noise and styrene exposure on hearing impairment in children.
In nonauditory physiological effects of noise, Wolfgang Babisch presented results from the HYENA (hypertension and exposure to noise near airports) study of six European airports. The report shows connections between increased blood pressure and exposure to noise from nighttime aircraft and 24-hour road traffic.
Presentations on the effects of combined exposure to noise and air pollution offered different results. Two large Dutch studies associated traffic intensity with excess cardiovascular mortality related to noise exposure of more than 65 dBA. The mortality was weakened by adjustment for air pollution but not vice versa. In contrast, Peter Lercher reported that small associations of particulate pollution on health disappeared after adjustment for noise exposure. Irene van Kamp showed no association between noise exposure and mental health either before or after the opening of the fifth runway at Amsterdam Airport Schiphol (Netherlands).
In the performance and behavior session, Bridget Shield reported that both internal classroom background noise and external noise such as road traffic, measured by LAmax (the maximum noise level measured for a specific period), strongly influenced school performance in 8-year-old London children. Göran Söderland outlined the "Moderate Brain Arousal" model, a novel theory on noise exposure in children that suggests that moderate noise exposure facilitates cognitive performance in children with attention deficit hyperactivity disorder.
In the noise and sleep session, Mathias Basner reported on an innovative use of ECGs in sleep studies as an indicator of EEG disturbance and on pupillography as an objective indicator of daytime sleepiness. In contrast to current thought, Evy Öhrström reported on an experimental study in which more awakenings occurred with rail noise than with road traffic noise. Traffic curfews are most effective at the end of the night when the likelihood of waking in noise greatly increases, according to Barbara Griefahn's studies.
In three cross-sectional studies of Alpine passes, all noise annoyance curves showed substantial departures from standard curves. Peter Lercher and Soogab Lee, using data from Austria and Korea, questioned whether the rail bonus is still generally applicable.
Sabine Jansen examined the reasons for increased population annoyance responses, particularly to aircraft noise, compared to earlier studies. The strongest association was to the year of the study, with influences also observed for scale type (11-point versus 5-point scales), postal versus telephone and interview surveys, and possibly greater numbers of noise events. In examining noise effect on annoyance and health, there is increased interest in the effects of number of events as well as sound intensity.
The policy session included discussion of the World Health Organization's evidence-based report on aircraft noise and health. Dieter Schwela showed the need for a strategic, step-by-step approach to noise control in low-income countries, where understanding of the public health impact of noise may be limited.
The congress included 77 presentations and 67 posters. The proceedings are available on the ICBEN Web site. Eight international noise teams (INT), comprising up to 10 experts in addition to the chair, contribute to the congress. INT categories are noise-induced hearing loss, noise and communication, non-auditory effects of noise, influence of noise on performance and behavior, effects of noise on sleep, community responses to noise, noise and animals, and interactions with other agents and contextual factors.
At ICBEN's business session this year, members voted to increase the meeting's frequency to every three years. Jerry Tobias, an ASHA member and past president of the congress, was instrumental in bringing it to the U.S. and making local arrangements. It was the first ICBEN Congress held in the United States since it was founded.
One of ICBEN's founding members, Tobias recalled how the congress first came about in 1968. ASHA had sponsored a meeting on noise as a public health hazard. Afterward, he met with two attendees, Gerd Jansen of Germany, and W. Dixon Ward, another ASHA member. Jansen suggested that noise researchers, representatives of industry and business, and government agencies should meet about the topic more frequently, so the three worked to start ICBEN. Tobias wrote the constitution and has been heavily involved with the organization ever since.