Journal of Speech and Hearing Research Vol.12 725-746 December 1969.
© American Speech-Language-Hearing Association
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrowCustom Print
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow My Folders
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Dirks, D. D.
Right arrow Articles by Malmquist, C. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Dirks, D. D.
Right arrow Articles by Malmquist, C. M.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Delicious   Add to Digg   Add to Facebook   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

Comparison of Frontal and Mastoid Bone-Conduction Thresholds in Various Conductive Lesions

Donald D. Dirks
Carolyn M. Malmquist
University of California School of Medicine, Los Angeles, California

Unoccluded and occluded bone conduction (BC) and Sensorineural Acuity Level (SAL) thresholds at the frontal bone and the mastoid process were compared on 60 subjects with conductive hearing loss. The results were based on calibrated norms obtained on 32 subjects with normal hearing and validated on 10 cases with sensorineural hearing loss. The mastoid BC thresholds for the entire conductive group were more depressed than comparable frontal measurements, but the average difference was only five dB. The threshold data for subjects with surgically confirmed middle-ear lesions (N = 38) were analysed in greater detail by dividing the group by frontal-mastoid differences and observed physical changes within the middle ear. Approximately 20% of the group showed frontal-mastoid differences that exceeded the normal range, and these cases had either malleus fixation or an ossicular discontinuity due to incus necrosis or absence of the incus. Average results for 17 cases with stapes fixation suggested that there were no frontal-mastoid differences and that both BC curves were somewhat similarly influenced by the middle-ear impairment. The SAL and occluded BC thresholds at the frontal bone were always in close agreement and differed from the unoccluded frontal-bone measurements for the conductive cases by the amount of the average occlusion effect observed for normals. The advantages of unoccluded bone conduction at the frontal bone are stressed, and the possible use of a comparison of BC thresholds at the two sites for diagnostic purposes is suggested.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Delicious Delicious   Add to Digg Digg   Add to Facebook Facebook   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?