| [Download PDF]
|Year : 2004 | Volume
| Issue : 25 | Page : 29--40
Self-reported tinnitus and noise sensitivity among adolescents in Sweden
SE Olsen Widen1, SI Erlandsson2,
1 University of Trollhättan/Uddevalla; Department of psychology, University of Göteborg, Sweden
2 Department of psychology, University of Göteborg, Sweden
S E Olsen Widen
University of Trollhättan-Uddevalla, Box 1236, S-462 28 Vänersborg
It seems to be a common opinion among researchers within the field of audiology that the prevalence of tinnitus will increase as a consequence of environmental factors, for example exposure to loud noise. Young people are exposed to loud sounds, more than any other age group, especially during leisure time activities, i.e. at pop concerts, discotheques and gyms. A crucial factor for the prevention of hearing impairments and hearing-related symptoms in the young population is the use of hearing protection. The focus of the present study is use of hearing protection and self-reported hearing-related symptoms, such as tinnitus and noise sensitivity in a young population of high-school students (N=1285), aged 13 to 19 years. The results show that the prevalence of permanent tinnitus and noise sensitivity, reported in the total group, was 8.7% and 17.1% respectively. Permanent tinnitus was not significantly related to level of socio-economic status, but age-related differences in the prevalence rates of experienced tinnitus and noise sensitivity were found to be significant. Older students reported such symptoms to a greater extent than younger students did. Those who reported tinnitus and other hearing-related symptoms protected their hearing to the highest extent and were the ones most worried.
|How to cite this article:|
Olsen Widen S E, Erlandsson S I. Self-reported tinnitus and noise sensitivity among adolescents in Sweden.Noise Health 2004;7:29-40
|How to cite this URL:|
Olsen Widen S E, Erlandsson S I. Self-reported tinnitus and noise sensitivity among adolescents in Sweden. Noise Health [serial online] 2004 [cited 2020 Jul 2 ];7:29-40
Available from: http://www.noiseandhealth.org/text.asp?2004/7/25/29/31649
Tinnitus is characterised as one or more sounds perceived in one or in both ears, alternatively perceived as being located in the head, without any external source of sound (Hiller and Goebel, 1999). According to Davies (1995) approximately 45% of the general population have experienced tinnitus, at least once in their lives. A majority of those can presumably be expected to experience a sound of very short duration, or to habituate to the sound without any further complications. Coles et al. (1981) reported that approximately 10% of the adult population in Great Britain had tinnitus. Later results presented by Coles (1984) suggested a higher prevalence rate of tinnitus, approximately 18% of the general population. Axelsson and Ringdahl (1989) found in a prevalence study in Sweden that 10-15% reported tinnitus and about 2% of the population had a form of tinnitus that they experienced as plaguing them all day.
A common opinion among researchers within the field of audiology is that the prevalence of tinnitus will increase as a consequence of environmental factors, for example exposure to loud noise. Arguably, exposure to loud noise may increase the risk of physiological damage to the auditory organ which, in turn, can lead to tinnitus (Kroener-Herwig, et al., 2000). Although tinnitus can be a symptom of an illness that can be managed and treated, for example acoustic neuroma or otosclerosis, the most common underlying cause of tinnitus is associated with relatively small changes in the cochlea (Vernon and Moller, 1995). Clinical studies have shown that people suffering from tinnitus are at a high risk of developing serious psychological disturbances or serious psychological distress (Hiller and Goebel, 1998). Whether or not individuals suffer or are annoyed by tinnitus seems to be associated with experienced stress in their life situation (Erlandsson, 1990) and with the experience of other people's attitudes towards tinnitus (Erlandsson, et al., 1992).
Sensitivity to sound can be understood from two different angles according to Stansfeld (1992). First of all, noise and sound are important for people who are sensitive to sound. Such individuals tend to pay attention to sounds and differentiate sounds more often than others do. Furthermore, they tend to perceive sounds as more threatening and experience lesser control over the situation compared to those who are not sensitive to noise. Secondly, people sensitive to noise react more heavily to unexpected sounds than the non-sensitive, which implies that it takes longer for them to habituate to a sound. People who are sensitive to noise consequently experience more threats from sounds, and have a general tendency to be more irritated, irrespective of the sound exposure. Stansfeld (1992) assumes that these circumstances can explain the relationship between noise sensitivity and mental health. Accordingly, it may explain why noise sensitivity can be understood as a vulnerability factor in terms of mental health (Stansfeld, 1992).
Epidemiological research has generated many consistent results showing the existence of relationships between social environment, socioeconomic status (SES) and health. The studies find, as a rule, that individuals from groups with lower SES have more problems with health than those from groups with higher SES (Backlund, et al., 1996; Frank and Mustard, 1994). Generally, the aims of measuring SES have been to gain information about people's access to social and economic resources. One of the most used socioeconomic indicators is education and professional position (Duncan, Daly, McDonough and Williams, 2002). Most explanations of SES- related health status have focused on external factors such as poverty, bad living conditions and undernourishment. (Chen, et al., 2002). Children are born into different socio-economic groups, with differing life experiences, attitudes, norms and beliefs, which can have an effect on their health. When SES increases risk factors and causes of mortality seem to decrease. Likewise, we find a decrease in the prevalence rates of asthma, visual and auditory problems, accidents and other illnesses such as ear infections (Chen et al., 2002).
To be exposed to leisure time noise may contribute to the prevalence of noise-induced hearing impairments among adolescents (Yaremchuk and Kaczor, 1999). Hearing loss, caused by noise exposure at work or in leisure time, is the most common form of sensorineural hearing impairment after presbyacusis. Hearing loss and tinnitus in the younger generation are commonly seen as a consequence of heavy noise exposure at pop concerts and discotheques (Gote et al., 1992). Young people exposed to significant noise (≥97 dB NIL) have been found to be three times more likely to report tinnitus compared to those exposed to lesser noise (Davis, et al., 1998). According to Davies et al., young people who reported tinnitus differed, depending on the level of social noise exposure, as regards their pure tone thresholds, their speech in noise tests results, their otoacoustic emissions and also with regard to problems concerning hearing. The effects of social noise exposure on hearing in young people have also been investigated by Meyer-Bisch (1996). Significant differences regarding auditory complaints e.g. the presence of tinnitus and/or hearing fatigue, were found between those who regularly attended discotheques when compared to control groups. Damage to hearing was found in those who made frequent use of personal stereos players or who regularly went to concerts, although this damage, however, did not appear among those who frequently went to discotheques.
Noise induced hearing loss can be avoided by decreasing damaging exposure to noise by the use of hearing protection (Rabinowitz, 2000). Heavy noise exposure can also give rise to changes in hearing levels, so called Noise Induced Threshold Shifts (NITS). NITS can be permanent or temporary in character depending on the level of sound. A large population study performed in the USA, including 5249 children and young adults aged 6 to 19 years, showed that approximately 12.5% of the sample had NITS (Niskar, et al., 2001). The researchers used The Third National Health and Nutrition Examination Survey (NHANES III), which is a national population-based cross-sectional study based on voluntary participation. Methods and data collection included household interviews, audiometric tests, socio-demographic variables, ethnic origin and economic conditions measured by The Poverty Income Ratio (PIR). One important result of this study was that children and young adults of parents with low PIR had the highest prevalence of NITS, which points in the direction of socio-economic differences.
Exposure to loud noise in the young population increases with age. One reason seems to be that older adolescents attend pop concerts and go to discotheques more frequently than younger adolescents do. To experience temporary tinnitus and hearing loss after activities with loud music is rather common among young women and men. Leisure time noise can be one of the most important reasons for the development of noise induced hearing loss in the young population. The effects of constantly being exposed to loud levels of noise can manifest themselves later in life. Jokitulppo, Bjork and Akaan- Pentilla (1997) showed in their study on noise exposure among teenagers, that there were significant differences between the sexes in choice of leisure time activities. Activities with most exposure to severe noise (playing in a rock band, take part in motor sports, shooting etc.) were preferred by boys. However, few studies have been undertaken regarding exposure to loud noise and the prevalence of noise sensitivity and tinnitus among adolescents. Almost no studies have focused on young people and the use of hearing protection in noisy activities. The area of research is of special interest today, as the awareness of the damaging effects of loud levels of noise during leisure time activities might have increased in recent years among adolescents in Sweden. During 1999 and 2000 the Swedish Association for the Hearing Impaired (HRF) organized activities focusing on noise and hearing prevention around the country.
The aim of the present study was to explore the prevalence of tinnitus and noise sensitivity among young people in Sweden and secondly, to describe their habits regarding noise exposure and the use of hearing protection.
The questionnaire used in the study consists of demographic and background information, (52 items) and an instrument for the measurement of attitudes to noise "Youth Attitude to Noise Scale" (YANS, 18 items, Olsen and Erlandsson, 2004). The part including the YANS will be reported in a forthcoming article. The demographic questions concerned gender, age, school, educational program and socio-economic status of parents. Questions about both parents' education and occupational status were asked in order to determine the SES of the family, based on the Hollinghead Four Factor Index of Social Status (Hollinghead, 1975; Swedish version, Broberg, 1992). This information was used to classify the SES of the child.
Questions related to hearing (Hearing Symptom Description, HSD, Erlandsson and Olsen 2004a) concerned for example the experience of permanent tinnitus, ear infections, noise sensitivity, experience of buzzing ears/ear pain related to different activities like pop concerts and discotheques and finally, experience of temporary tinnitus lasting longer than 24 hours. The questions regarding permanent tinnitus and noise sensitivity were asked in the following way: "Do you have permanent tinnitus (buzzing or ringing) in your ears all the time?" "Do you consider yourself to be oversensitive to noise?" The questions about pain or peeps/buzzing in the ears were formulated as: "Have you ever experienced pain in the ears associated with loud noise?" (yes/no), and, "Have you ever experienced peeps or buzzing in your head or ears after noise exposure?" If the respondent answered yes to these questions, the participant could mark at what activities these symptoms were experienced. Finally, a question about temporary tinnitus was asked in the following way, "Have you ever had temporary tinnitus continuing for 24 hours or longer" (yes/no).
Additionally, two different ways of reasoning were given as alternatives to a question regarding the experience of occasional auditory symptoms (peeps or buzzing) to those who answered that they had experienced such symptoms. The first alternative: "the buzzing might disappear in a while" can be a sign of denial or trying to ignore the sound. "Imagine, if the buzzing does not disappear and I have to put up with it for the rest of my life" can be a sign of worry because of the symptom. Furthermore, a question was asked about whether or not respondents were worried before attending noisy activities because of previous experience of hearing problems. Finally, questions were asked about the participants' habits regarding exposure to loud noise and the use of hearing protection in those situations.
Based on the questions regarding the experience of tinnitus and noise sensitivity, the participants were divided into four groups, so called symptom-groups. Those were: group 1, experience of both tinnitus and noise sensitivity (TNS); group 2, experience of tinnitus only (T); group 3, experience of noise sensitivity only (NS); and group 4, no hearing problems (NHP). The symptom-groups were compared according to use of hearing protection and whether or not the participants were worried prior to attending activities where loud noise exposure would be expected.
Finally, adolescents habits regarding noisy activities and use of hearing protection were measured by Adolescents Habits and Hearing protection (AHH) (Erlandsson and Olsen, 2004b).
Frequency tables and the results of chi-squared tests are shown below.
Participants and dropout rates
Questionnaires were sent out to 1547 young individuals between 13 and 19 years of age. The number of participants who answered the questionnaire was 1324, indicating an external dropout rate of 14.4%. Thirty-nine questionnaires (2.5%) were incompletely filled in and regarded as internal dropouts. In total, 262 questionnaires (16.9%) were not complete and hence, 1285 participants were included in the study. The analysis, based on the four symptom groups, consisted of 1238 participants, with a dropout rate of 14 participants (1.1%) due to incomplete answers on questions regarding hearing-related symptoms [Table 5]. Furthermore 33 respondents were excluded from the group NHP (control group), since they had marked that they had a hearing impairment. The sample was divided into subgroups due to age, secondary school students (13-15 years of age), and upper secondary school students (16-19 years of age). [Table 1] presents an overview of the sample.
The questionnaires were distributed to eight different schools in Goteborg and Vanersborg.
Five upper secondary schools and one secondary school were selected in Goteborg and one upper secondary school and one secondary school in Vanersborg. Goteborg is the second largest city in Sweden with 800,000 inhabitants including surrounding municipalities. Vanersborg is a county city of Vastra Gotaland, situated 90 kilometres north of Goteborg and has around 30,000 inhabitants. The educational programs did not differ between schools.
The heads of the schools were informed about the study by telephone and asked to give their permission to carry out the investigation. An information letter was sent out to teachers at the schools, asking them to distribute the questionnaire among their students at a convenient time. The completed questionnaires were put in envelopes collected by one of the investigators. Permission to take part in the study was given by the parents of the younger participants who signed a letter of consent. A teacher was present when the students were completing their questionnaires, in case they had any questions on it. The time needed to answer the questionnaire was approximately 20 minutes.
Number of participants reporting permanent tinnitus, noise sensitivity, temporary tinnitus and ear pain
The experience of permanent tinnitus was reported by 109 participants, corresponding to 8.7% of the total group studied. 10.3% of upper secondary school students reported permanent tinnitus compared to 6.8% of secondary school students, showing a significant difference between the two groups (χ 2 = 4.93; df = 1; p 2 = 9.27; df = 1; p 2 = 7.31; df = 1; p 2 = 15.88; df = 1; p Symptom-groups and ear infections in childhood
The frequency of repeated ear infections in childhood, so called otitis media, differed significantly between the symptom-groups (χ 2 = 8.39; df = 3; p Two alternative ways of reasoning in relation to gender, age and SES
[Table 4] illustrates two alternative ways of reasoning, having experienced temporary hearing-related symptoms. The ways of reasoning were analysed according to gender, age and SES. Both girls and boys used the first alternative, (denial) more often. However, significantly more girls than boys (χ 2 = 32.39; df = 1; p 2 = 8.57; df = 2; p Comparisons between symptom-groups concerning worry before attending noisy activities and use of hearing protection
The majority of the participants (78.1% of N = 1238) did not report any hearing problems. Of the remaining participants, 13.2% experienced noise sensitivity, 4.7% tinnitus and 4.0% both tinnitus and noise sensitivity [Table 5].
Significant differences were found between the symptom-groups regarding worry at the prospect of activities where loud noise could be expected (χ 2 = 101.10; df = 3; p 2 = 36.66; df = 3; p 2 = 63.62; df = 3; p 2 = 76.10; df = 1; p 2 = 10.25; df = 1; p normal and pathological tinnitus. Normal tinnitus is experienced by most people without hearing loss, lasting for less than five minutes less than once a week. Pathological tinnitus lasts for more than five minutes more than once a week and is usually experienced by people with a hearing loss. Dauman and Tyler's (1992) definition of pathological tinnitus is questionable, as it is rather common to experience sounds within the head or in the ears, without this being pathological. It is natural for most normal hearing individuals to experience some form of sounds in the ears/head in e.g. a sound proof chamber. Heller and Bergman (1953) found that this was true for 94% of a group of 80 normal hearing individuals. Heller and Bergman assumed that it is not possible to eliminate tinnitus completely since sub audible sounds are present in nearly all people. In the present study the criteria for definitions of permanent and temporary tinnitus are intentionally made very strict in order to focus on adolescents who we believe are at risk for developing hearing disorders. To have experienced temporary tinnitus lasting for longer than 24 hours is a serious symptom, which nearly 22% of the adolescents in the present study reported. If we had chosen a broader definition (e.g. Dauman and Tyler's) the prevalence rates in the present study would have been even greater. Another important finding in the present study is that about 40% of the adolescents reported that they had experienced temporary peeps/buzzing after discotheque and concert visits. It is relatively common that young individuals experience hearing problems after noise exposure. This also stresses the need for lowering the sound levels in the society, to prevent young people from future hearing impairments.
Noise sensitivity was reported by 17.1% of the participants in this study. Again, this problem was more common among upper secondary school students (19.7%) than among secondary school students (14%). The four symptom groups, TNS, T, NS, and NHP were compared according to whether or not the participants were worried prior to attending activities where loud noise exposure could be expected. We found significant difference between the four symptom-groups, regarding worry before noise exposure. Most worried were those who reported both tinnitus and noise sensitivity. Approximately 45% of them reported worry. Least worried were participants with no hearing related symptom (NHP), of whom only 8% replied that they had been worried before noise exposure. Among those reporting tinnitus or noise sensitivity only, approximately 26% of each sub-group stated that they had been worried. A likely interpretation of these figures is that participants being troubled by ear symptoms are aware of the harmful effects of heavy noise exposure due to their own experiences. It may also lead to them being more worried about the exposure to loud sounds. An important question is whether or not knowledge and concern play important roles for how people think and act when visiting concerts and discotheques and whether or not these factors influence use of hearing protection in noisy situations.
Sixty-seven percent of those who reported having both tinnitus and noise sensitivity, stated that they used hearing protection when visiting concerts, compared to approximately 35% and 38% respectively of those reporting only one of these symptoms. In the group consisting of symptom-free participants, about 26% used hearing protection at concerts. The pattern repeated itself when discotheque visits were analysed, however, the numbers of participants who use hearing protection at discotheques is somewhat smaller. One hypothesis might be, that participants having experienced auditory symptoms, are more easily concerned by their symptoms and become more focused on sounds in general and therefore more aware of the importance of protecting the hearing, than is the case for participants who are free of symptoms. The results are also congruent with the implications of the Health Belief Model (HBM, Rosenstock, 1974). According to this model one important factor for changing behavior, is whether or not the individual is mentally prepared to accomplish the behavior, and if the behavior can be regarded as favourable or not. It is often not sufficient for the person to accomplish the desirable health behavior, hence there is a need for an additional factor. Such a factor can be regarded as a releaser or a "trigger", leading to a desire to change the behavior Rosenstock, (1974). In the case of hearing-related symptoms, the "trigger" can be, for example, tinnitus or noise sensitivity. Possibly, the combination of ear symptoms and worry at the prospect of being harmed by loud sounds can lead to more frequent use of hearing protection.
There was a gender difference in the study, regarding the two alternative ways of reasoning, when temporary hearing-related symptoms were experienced. The frequency of the girls compared to the boys choosing worry over denial was higher ("Imagine, if the buzzing does not disappear and I have to put up with it for the rest of my life"). It was also more common for older students to choose this form of reasoning. A difference was also found when the three SES groups were compared. More participants from homes with a high SES-level endorsed alternative 2, compared to participants from homes with low SES-level. Those two ways of reasoning can imply that there is a dividing line between those who are going to change their behavior and those who are not. It is likely that individuals, who are worried by e.g. temporary tinnitus, will protect their hearing in different ways, for example by starting to use hearing protection or avoiding activities where loud sounds will be expected to occur. Individuals who, on the other hand, ignore their symptoms, may run a risk of developing a noise-induced hearing impairment in the longer term. The choice of alternative 2 can therefore be seen as an adaptive way to behave under the current circumstances. A certain degree of concern and worry can be necessary in order for the individual to change her or his behavior.
In research on health behavior change, the Theory of Planned Behavior has been used as an explanatory model (TPB, Ajzen, 1991). TPB has attracted considerable attention, especially among social psychologists interested in identifying beliefs underpinning health behaviors that may be amenable to change (Rutter and Quine, 2002). TPB provides a theoretical account of the way in which attitudes, subjective norms and behavioral intentions are related. An individual's attitude towards a specific behavior or phenomenon implies an overarching valuation of the behavior or the phenomenon. The attitude can be affected by the individual's knowledge about a specific phenomenon (Rutter and Quine, 2002). For example, if a person is aware of the risks associated with noise exposure in terms of hearing impairments and tinnitus, it could be expected that this person would tend to hold a more negative attitude towards noise and would probably use some kind of hearing protection in a noisy environment.
In Sweden there has, for some time, been a discussion about the negative effects of noise and the importance of using earplugs. The Swedish Association for the Hearing Impaired (HRF) initiated a campaign called "Tinnitus year", that was held during 1999. The campaign resulted in a series of activities focusing on noise and hearing prevention around the country. One such activity was held during three days in February 2000 and directed towards secondary school pupils in Goteborg. The program included presentations by professionals in Psychology, Audiology and Hearing Technology about, for example, hearing-loss prevention, environmental noise and use of hearing protection. Psychological consultations for tinnitus suffering was also provided. Artists and Musicians Against Tinnitus (AMMOT) is a Swedish association for musicians. They have contributed to the event providing information about risk factors associated with being a professional musician and the importance of protecting one's hearing. Therefore, the finding that 11% of the respondents in the present study reported the use of earplugs at discotheques and 30% at concerts is of interest. One possible explanation is an increase in awareness in Swedish adolescents regarding the damaging effects of noise exposure and the importance of protecting their hearing. The part in this study that concerns the association between adolescents' attitudes towards noisy environments and the use of hearing protection, will be reported in a forthcoming article.
Of note in this study is that there was no significant difference in symptoms reported (tinnitus and noise sensitivity) between participants from high and low SES-levels. Niskar et al. (2001) found that more children from homes with low PIR had changes in hearing levels than children from homes with high PIR. It is possible that cultural differences between countries affect the prevalence of hearing impairments between SES groups.
Another reason might be that hearing has not been audiometrically measured in the present study. It is possible that small differences in hearing levels between the SES-groups would have been found, if we had measured them. Another possibility is that a cultural difference in children's and young people's ear-related health actually exists. This issue is the subject of a forthcoming study on young people's hearing and use of hearing protection in the USA and Sweden.
The authors are grateful for the funding provided by the Stinger foundation, The Swedish Association for the Hearing Impaired (HRF) and the University of Trollhattan / Uddevalla.
|1||Ajzen I. (1991)The theory of planned behaviour. Organisational Behavior and Human Decision Processes. 50: 179-211|
|2||Axelsson A. and Ringdahl A. (1989) Tinnitus - a study of its prevalence and characteristics. British Journal of Audiology. 23: 53-62|
|3||Backlund E., Sorlie P. D. and Johnson N. J. (1996) The shape of the relationship between income and mortality in the United States: Evidence from the national longitudinal mortality study. Annals of Epidemiology. 6: 12-20|
|4||Broberg A. (1992) Hollinghead Four Factor Index of Social Status. 1975, Swedish version. Unpublished manuscript. Department of Psychology, University of Goteborg, Sweden|
|5||Chen E., Boyce W. T. and Mattews K. A. (2002) Socioeconomic differences in childrens health: How and why do these relationships change with age? Psychological Bulletin. 128: 295-329|
|6||Coles R. R. A., Davis A. C. and Haggard M. P. (1981) Epidemiology of tinnitus. In: Tinnitus. D. Evered., and G. Lawrenson., eds. Pitman Books Ltd. Ciba Foundation Symposium, London, pp 16-34|
|7||Coles R. R. A. (1984) Epidemiology of tinnitus: (1) Prevalence. Journal of Laryngol Otology. 9: 7-15|
|8||Davis A. C. (1995) Hearing in Adults. London, Whurr Publ. Ltd.|
|9||Davis A. S., Lovell E. A., Smith P. A. and Ferguson M. A. (1998) The contribution of social noise to tinnitus in young people - a preliminary report. Noise and Health 1: 40-46|
|10||Dauman, R., and Tyler, R. S. (1992). Some considerations on the classification of tinnitus. In J. M. Aran., and R. Dauman., eds. Proceedings of the fourth international tinnitus seminar Bordeaux, France, pp 225-229|
|11||Duncan G. J., Daly M. C., McDonough P. and Williams D. R. (2002) Optimal indicators of socioeconomic status for health research. American Journal of Public Health. 92: 1151-1157|
|12||Erlandsson S. I. (1990) Tinnitus: Tolerance or threat? Psychological and psychophysiological perspectives, PhD dissertation (unpublished). Department of Psychology, University of Goteborg, Sweden|
|13||Erlandsson S. I., Hallberg L. R.-M. and Axelsson A. (1992) Psychological and audiological correlates of perceived tinnitus severity. Audiology. 31: 168-179|
|14||Erlandsson, S. I., and Olsen, S. E. (2004a). Hearing Symptom Description (HSD). In: Olsen, S. E. (2004). Psychological aspects of adolescents' perceptions and habits in noisy environments. Licentiate dissertation (unpublished). Department of Psychology, University of Goteborg, Sweden|
|15||Erlandsson, S. I. and Olsen, S. E. (2004b) Adolescents' Habits and use of Hearing protection (AHH). In: Olsen, S. E. (2004). Psychological aspects of adolescents' perceptions and habits in noisy environments. Licentiate dissertation (unpublished). Department of Psychology, University of Goteborg, Sweden|
|16||Frank J. W. and Mustard J. F. (1994) The determinants of health from a historical perspective. Daedalus. 123: 1-19|
|17||Gothe C. J., Cynker I., Lind M. L., Blomberg R., Svensson E. B. and Ytterlind A. (1992) Bullerexponering av elektroniskt forstarkt musik-rockkonserter medfor risk for horselskada. [Noise exposure at rock concerts may cause hearing impairments] Stockholm: Ldkartidningen. 43: 3579-3580|
|18||Heller M. F., and Bergman., M. (1953) Tinnitus Aurium in normally hearing persons. Annual Otology, 62: 101-121|
|19||Hiller W. and Goebel G. (1998) Co-morbidity of psychological disorders in patients with complex chronic tinnitus. In: Tinnitus. Psychosomatic aspects of complex chronic tinnitus. Goebel G., eds. Quintessence, London, pp 63-84|
|20||Hiller W. and Goebel G. (1999) Assessing audiological, pathophysiological, and psychological variables in chronic tinnitus: A study of reliability and search for prognostic factors. International Journal of Behavioral Medicine. 6: 312-331|
|21||Hollinghead, A. B. (1975) The four-factor index of social status. (Unpublished manuscript, Yale University).|
|22||Jokitulppo J. S., Bjork A. and Akaan - Penttila E. (1997) Estimated leisure noise exposure and hearing symptoms in Finnish teenagers. Scandinavian Audiology. 6: 257-262|
|23||Kroener-Herwig B., Biesinger E., Gerhards F., Goebel G., Greimel K. V. and Hiller W. (2000) Retraining therapy for chronic tinnitus: A critical analysis of its status. Scandinavian Audiology. 29: 67-78|
|24||Meyer-Bisch C. (1996) Epidemiological evaluation of hearing damage related to strongly amplified music (Personal Cassette Players, Discotheques, Rock Concerts) - High-definition audiometric survey on 1364 subjects. Audiology. 35: 121-142|
|25||Niskar A. S., Kieszak S. M., Holmes A. E., Esteban E., Rubin C. and Brody D. J. (2001) Estimated prevalence of noise-induced hearing threshold shifts among children 6 to 19 years of age: The third national health and nutrition examination survey, 1988-1994, United States. Pediatrics. 108: 40 - 43|
|26||Olsen, S. E. and Erlandsson, S. I. (2004) Youth Attitude to Noise Scale (YANS). In: Olsen, S. E. (2004). Psychological aspects of adolescents' perceptions and habits in noisy environments. Licentiate dissertation (unpublished). Department of Psychology, University of Goteborg, Sweden|
|27||Rabinowitz P. M. (2000) Noise induced hearing loss. American Family Physician. 61: 2749-2757|
|28||Rosenhall U., Sixt E., Sundh V. and Svanborg A. (1993) Correlation between presbyacusis and extrinsic noxious factors. Audiology-Basel. 4: 234|
|29||Rosenstock I. M. (1974) The Health Belief Model and preventive health behavior. Health Education Monographs. 2: 354 - 386|
|30||Rutter D. and Quine L. (2002) Changing Health Behaviour: Intervention and Research With Social Cognition Models. Buckingham Philadelphia, Open University Press.|
|31||Stansfeld S. A. (1992) Noise, noise sensitivity and psychiatric disorder: epidemiological and psychophysiological studies. Psychological Medicine Monograph Supplement 22. Cambridge University Press|
|32||Vernon J. A. and Moller A. R. (1995) Mechanisms of tinnitus. Boston: Allyn and Bacon|
|33||Yaremchuk K. L. and Kaczor J. C. (1999) Noise levels in the health club setting. ENT-Ear, Nose and Throat Journal. 78: 54 -57|