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ABSTRACT: The objectives were to measure the occlusion effect produced by three earphones-circumaural, supra-aural, and insert-and to compare air- and bone-conduction thresholds obtained with manual and automated methods for subjects with sensorineural hearing loss.
Acoustic and psychoacoustic occlusion effects were measured with each earphone. Manual and automated, air- and bone-conduction thresholds were compared. Study sample: Occlusion effects were measured for six adult subjects with normal external and middle ears. Pure-tone thresholds were measured for nineteen ears of thirteen subjects with sensorineural hearing loss.
The supra-aural earphone produced the largest occlusion effects, followed by the insert and circumaural earphones. Some systematic differences in air-conduction thresholds were found for the two procedures that may be attributable to earphone differences. A large air-bone gap at 4 kHz, reported in a previous study, was replicated.
From 0.5 to 8.0 kHz, occlusion effects produced by the circumaural earphone are sufficiently small that covering the ear does not appreciably alter bone-conduction thresholds. Air-conduction threshold differences warrant further study to determine if reference equivalent threshold sound pressure levels for the two earphones produce equivalent thresholds. The large air-bone gap at 4 kHz suggests the possibility of an incorrect reference equivalent threshold force level at that frequency.
International journal of audiology 07/2011; 50(7):440-7. · 1.34 Impact Factor
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ABSTRACT: This study was designed to evaluate an automated pure-tone audiometric procedure (AMTAS(®)) for 4-8 year-old children, and a quality assessment method (QUALIND(®)) that predicts the accuracy of the test.
Children were tested with AMTAS and conventional manual air-conduction audiometry. A group of adults was tested for comparison. Study sample: Eighty-one 4-8 year-old children and 15 adults. Most had normal hearing.
For most subjects (93% of adults and 91% of children) differences between AMTAS and manual thresholds were similar to differences that occur when two experienced audiologists test the same subjects. QUALIND detected the inaccurate audiograms with a sensitivity of 71% and a specificity of 91%. When inaccurate audiograms identified by QUALIND are excluded, the accuracy of AMTAS is similar to the accuracy of manual audiometry.
AMTAS produces accurate air-conduction audiograms in a high proportion of 4-8 year-old children and adults. QUALIND successfully identified most inaccurate AMTAS audiograms. The method can decrease the cost and increase efficiency and accessibility of hearing testing.
International journal of audiology 03/2011; 50(7):434-9. · 1.34 Impact Factor
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ABSTRACT: Three studies are reported assessing the validity of AMTAS, an automated method for obtaining an audiogram, including air- and bone-conduction thresholds (stimuli delivered by a forehead-placed transducer) with masking noise presented to the non-test ear. In Study 1, six subjects at each of three sites were tested using manual audiometry by two audiologists at each site. The mean differences between the audiograms for the paired audiologists provided a measure of the reliability of traditional audiometry. In Study 2, thirty subjects (5 normal hearing, 25 hearing impaired) were tested using AMTAS and manual audiometry. For air-conduction thresholds, AMTAS-manual differences were similar to inter-tester differences in Study 1, but for bone-conduction thresholds, the former were larger. Two possible sources of the greater differences were identified, (1) incorrect reference-equivalent threshold force levels for forehead bone conduction, and (2) a differential effect of middle-ear disease on forehead and mastoid bone-conduction thresholds. In Study 3, intersubject variability was studied for forehead and mastoid bone-conduction thresholds. The results indicate similar variability for the two placement sites.
International journal of audiology 03/2010; 49(3):185-94. · 1.34 Impact Factor
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ABSTRACT: The rationale for automating pure-tone audiometry based on the need for hearing tests and the capacity of audiologists to provide testing is presented. The personnel time savings from automated testing are analyzed. Some possible effects of automated testing on the profession are explored.
Need for testing was based on prevalence of hearing impairment, number of normal hearing patients seen for testing, and an assumption of the frequency of testing. Capacity is based on the number of audiologists and the number of audiograms performed in a typical workday. Time savings were estimated from the average duration of an audiogram and an assumption that 80% can be automated.
A large gap exists between the need and the capacity of audiologists to provide testing. Automating 80% of audiograms would only partially close the gap. A significant time savings could accrue, permitting reallocation of time for doctoral level services.
Although certain jobs could be affected, the gap between capacity and need is so great that automated audiometry will not significantly affect employment. Automation could increase the number of hearing impaired patients that could be served. The reallocation of personnel time would be a positive change for our patients and our profession.
American Journal of Audiology 11/2008; 17(2):109-13. · 0.87 Impact Factor
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ABSTRACT: This study was designed to characterize a large database of audiometric records from an academic health center Audiology clinic for the purpose of determining the distributions of hearing loss configuration, severity, and site of lesion.
: Using AMCLASS, a validated tool for classifying audiograms described in a previous report, the audiometric configuration, severity, and site of lesion was determined for patients grouped according to the completeness of the audiometric record. Complete air conduction testing at six octave frequencies in both ears was required for inclusion. Patients were grouped according to the quantity of bone conduction thresholds in the record: both ears tested, one ear tested, or neither ear tested. All other records were discarded leaving 23,798 records of 16,818 patients for analysis. All analyses were conducted for all remaining records and with repeat tests excluded.
The effect of removing repeat audiograms had remarkably little effect on the distributions. Sloping hearing losses dominated the distributions of configuration. One-third of all records indicated normal hearing in at least one ear and one fourth had normal hearing in both ears. Mild and moderate hearing losses were equally prevalent, each contributing 40% to 45% of the cases with hearing loss. Sensorineural was the most prevalent site of lesion, representing about 45% of cases and just over half the cases with hearing loss.
Prevalence rates of hearing loss configurations, severities, and sites of lesion are provided against which analyses of other databases can be compared. The results may be useful for counseling patients regarding the relationship of their hearing loss to that of a large population. The high number normal-hearing people in the database suggests that estimates of the need for hearing testing based on prevalence of hearing loss may underestimate the number of people who seek or are referred for hearing evaluation.
Ear and hearing 09/2008; 29(4):524-32. · 2.06 Impact Factor
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ABSTRACT: An algorithm for identifying asymmetric hearing loss (AHL) can be constructed that performs as well or better than expert judges.
AMCLASS is a method for classifying audiograms based on configuration, severity, site of lesion, and interaural asymmetry. The development and clinician validation for all but asymmetry were reported separately. In this report, an algorithm for identifying AHL is described. Using the clinician-validated algorithm, the prevalence of AHL in a database from an academic health center audiology clinic was analyzed.
: Five expert clinicians classified 199 audiograms as symmetric or asymmetric. Interjudge agreement was analyzed for each pair of judges and between each judge and the consensus of the panel. An algorithm was constructed based on the set of rules that maximized agreement between AMCLASS and judges. Using the clinician-validated algorithm, the prevalence of AHL was analyzed for groups based on quantity of bone conduction testing, hearing loss configuration, severity, and site of lesion.
There was substantial disagreement among judges that was similar to interjudge comparisons for other medical tests. Average agreement between AMCLASS and the judges was higher than agreement between the best judge and the consensus of the judges. Approximately 50% of all patients and 55% of patients with sensorineural hearing loss were classified as AHL by the clinician-validated algorithm.
The algorithm met the goal of equaling or exceeding the performance of expert judges. The prevalence of AHL was higher than expected and suggests that the algorithm is not useful for screening for acoustic neuroma or other conditions. Perhaps, a criterion based on the magnitude of the asymmetry would better serve that purpose. The symmetry category provided by AMCLASS provides a determination of clinically significant AHL that agrees with the consensus of expert judges.
Ontology & Neurotology 07/2008; 29(4):422-31. · 1.90 Impact Factor
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ABSTRACT: Hearing losses are frequently described by categories that characterize the configuration, severity, and site of lesion from a pure-tone audiogram. Although many category descriptors are in common use, there are no standard definitions of those terms, nor have the category definitions been validated against current clinical practice. The development and validation of AMCLASStrade mark is described. To validate the classification method, five expert judges selected configuration, severity, and site of lesion categories for 231 audiograms that varied widely in audiometric configuration. Interjudge comparisons indicated that expert judges frequently disagree on how they describe an audiogram. Category definitions were adjusted to maximize agreement between AMCLASStrade mark and the consensus of the judges. The final set of category definitions produced categories that agreed with the consensus more often than the average agreement between pairs of judges.
International journal of audiology 01/2008; 46(12):746-58. · 1.34 Impact Factor
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ABSTRACT: As audiology strives for cost containment, standardization, accuracy of tests, and accountability, greater use of automated tests is likely. Highly skilled audiologists employ quality control factors that contribute to test accuracy, but they are not formally included in test protocols, resulting in a wide range of accuracy, owing to the various skill and experience levels of clinicians. A method that incorporates validated quality indicators may increase accuracy and enhance access to accurate hearing tests. This report describes a quality assessment method that can be applied to any test that (1) requires behavioral or physiologic responses, (2) is associated with factors that correlate with accuracy, and (3) has an available independent measure of the dimension being assessed, including tests of sensory sensitivity, cognitive function, aptitude, academic achievement, and personality. In this report the method is applied to AMTAS, an automated method for diagnostic pure-tone audiometry.
Journal of the American Academy of Audiology 02/2007; 18(1):78-89. · 1.30 Impact Factor
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ABSTRACT: With the rapid implementation of universal newborn hearing screening (UNHS) programs, a test of middle-ear function for infants is urgently needed. Recent evidence suggests that 1 kHz tympanometry may be effective. Normative data are presented for newborn intensive care unit (NICU) graduates tested at a mean age of 3.9 weeks (Study 1) and full-term infants tested at 2-4 weeks (Study 2) who passed an otoacoustic emissions (OAE) screen. Nearly all infants tested had single-peaked tympanograms. The norms are evaluated for a group of full-term infants who were screened with OAE (Study 3) and two groups of infants (NICU patients and well babies) who were not screened by OAE (Study 4). The 5th percentile for static admittance for NICU and full-term babies was identical, allowing a sinngle pass-fail criterion. Using that criterion, well babies who passed an OAE screen (Study 3) yielded a 91% pass rate. Those who passed the OAE screen had substantially higher 1 kHz static admittance than those who failed, suggesting a strong relationship between middle-ear transmission characteristics and OAE responses. The pass rate was lower for newborn well babies and NICU graduates who were not screened by OAE (Study 4).
Journal of the American Academy of Audiology 10/2003; 14(7):383-92. · 1.30 Impact Factor
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ABSTRACT: Tympanometry has widespread clinical use in the diagnosis of middle ear pathology. Low static admittance and high tympanometric width are highly correlated with the presence of effusion. Negative tympanometric peak pressure is not clearly associated with otitis media but can predict which children may be at risk for developing otitis. Age-specific norms have been published for these tympanometric quantities.
Conventional tympanometry with a probe tone of 226 Hz has not proven useful in newborns, but there is evidence that high-frequency tympanograms, particularly at a probe frequency of 1000 Hz, can detect the presence of middle ear effusion in very young infants. Alternatives to tympanometry, such as wide-band reflectance, are also under investigation for this population.
Current Opinion in Otolaryngology & Head and Neck Surgery 09/2002; 10(5):387-391. · 1.83 Impact Factor
