liu.seSearch for publications in DiVA
Change search
ReferencesLink to record
Permanent link

Direct link
Hearing threshold levels for an otologically unscreened, non-occupationally noise-exposed population in Sweden
Linköping University, Department of Clinical and Experimental Medicine, Technical Audiology . Linköping University, Faculty of Health Sciences.
Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery . Linköping University, Faculty of Health Sciences.
2002 (English)In: International Journal of Audiology, ISSN 1499-2027, Vol. 41, no 3, 180-194 p.Article in journal (Refereed) Published
Abstract [en]

The aim of this study was to investigate the hearing threshold levels (HTL) of an otologically unscreened population in Sweden. The results are compared to other studies of otologically unscreened populations, and a new mathematical model of hearing threshold levels as a function of age is presented. The subjects were males and females aged from 19 to 81 years, selected from the province of ╓sterg÷tland in Sweden. The test battery included otoscopy, tympanometry, pure-tone audiometry, and a questionnaire. Subjects exposed to occupational noise were excluded, and in total 603 persons were included in the analysis. The regression analysis resulted in different hyperbolic tangent functions with four parameters: HTL = A + B ╫ tanh(C ╫ age + D).

Place, publisher, year, edition, pages
2002. Vol. 41, no 3, 180-194 p.
National Category
Medical and Health Sciences
URN: urn:nbn:se:liu:diva-13516OAI: diva2:20890
Available from: 2003-03-20 Created: 2003-03-20 Last updated: 2009-05-20
In thesis
1. On noise and hearing loss: Prevalence and reference data
Open this publication in new window or tab >>On noise and hearing loss: Prevalence and reference data
2003 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Noise exposure is one of the most prevalent causes of irreversible occupational disease in Sweden and in many other countries. In hearing conservation programs, aimed at preventing noise-induced hearing loss, audiometry is an important instrument to highlight the risks and to assess the effectiveness of the program. A hazardous working environment and persons affected by it can be identified by monitoring the hearing thresholds of individual employees or groups of employees over time. However, in order to evaluate the prevalence of occupational noise-induced hearing loss, relevant reference data of unexposed subjects is needed.

The first part of this dissertation concerns the changes in hearing thresholds over three decades in two occupational environments with high noise levels in the province of Östergötland, Sweden: the mechanical and the wood processing industries. The results show a positive trend, with improving median hearing thresholds from the 1970s into the 1990s. However, the hearing loss present also in the best period, during the 1990s, was probably greater than if the occupational noise exposure had not occurred. This study made clear the need for a valid reference data base, representing the statistical distribution of hearing threshold levels in a population not exposed to occupational noise but otherwise comparable to the group under study.

In the second part of the dissertation, reference data for hearing threshold levels in women and men aged from 20 to 79 years are presented, based on measurements of 603 randomly selected individuals in Östergötland. A mathematical model is introduced, based on the hyperbolic tangent function, describing the hearing threshold levels as functions of age. The results show an age-related gender difference, with poorer hearing for men in age groups above 50 years.

The prevalence of different degree of hearing loss and tinnitus is described for the same population in the third part of the dissertation. The overall prevalence of mild, moderate, severe or profound hearing loss was 20.9% collectively for women and 25.0% collectively for men. Tinnitus was reported by 8.9% of the women and 17.6% of the men. Approximately 2.4% of the subjects under study had been provided with hearing aids. However, about 7.7% were estimated to potentially benefit from hearing aids as estimated from their degree of hearing loss.

Noise-induced hearing loss primarily causes damage to the outer hair cells of the inner ear. The fourth and last part of the dissertation evaluates the outer hair cell function, using otoacoustic emission measurements (OAE). Prevalence results from three different measuring techniques are presented: spontaneous otoacoustic emissions (SOAE), transient evoked otoacoustic emissions (TEOAE) and distortion product otoacoustic emissions (DPOAE). Gender and age effects on the recorded emission levels were also investigated. Women showed higher emission levels compared to men and for both women and men the emission levels decreased with increasing age. The results from the OAE recordings were shown to be somewhat affected by the state of the middle ear. The study included tympanometry, and the relation of the outcome ofthis test to the otoacoustic emissions is described, where high middle ear compliance resulted in low emission level. Reference data for the tympanometric measurements are also presented.

The results of this project form an essential part of the important work against noiseinduced hearing loss, which needs continuous monitoring. The reference data presented here will provide a valid and reliable data base for the future assessment of hearing tests performed by occupational health centres in Sweden. This data base will in turn prove useful for comparison studies for Sweden as a responsible fellow EU member country setting high standards for work force safety. The statistical distribution of hearing threshold levels as a function of age for men and women in tabulated form is available on the Swedish Work Environment Authority (Arbetsmiljöverket) web site:

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2003. 86 p.
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 797Linköping University Medical Dissertations, ISSN 0345-0082 ; 774
irreversible occupational disease, noise-induced hearing, noise-induced measurements (OAE), spontaneous otoacoustic emissions (SOAE), transient evoked otoacoustic emissions (TEOAE), distortion product otoacoustic emissions (DPOAE)
National Category
urn:nbn:se:liu:diva-4992 (URN)91-7373-592-2 (ISBN)
Public defence
2003-02-28, Elsa Brändströms föreläsningssal, Hälsouniversitetet, Campus US, Linköpings universitet, Linköping, 13:00 (English)
Available from: 2003-03-20 Created: 2003-03-20 Last updated: 2012-01-25Bibliographically approved

Open Access in DiVA

No full text

Other links

Link to articleLink to Ph.D. thesis

Search in DiVA

By author/editor
Johansson, MagnusArlinger, Stig
By organisation
Technical Audiology Faculty of Health SciencesOto-Rhiono-Laryngology and Head & Neck Surgery
Medical and Health Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 128 hits
ReferencesLink to record
Permanent link

Direct link