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O Fjermedal

Publications and source records attributed to O Fjermedal.

12 recordsLinked to original sources
PubMed1990

Reproducibility of hearing threshold measurements. Supplementary data on bone-conduction and speech audiometry.

The reproducibility of bone-conduction pure-tone audiometry and speech recognition thresholds has been tested in groups of normal-hearing subjects. Each person was tested twice during the same day, and the test-retest difference was calculated. The reproducibility is presented as the standard deviation of this difference. Bone-conduction threshold measurements have a high degree of test-retest precision, whereas air-bone gaps show a large range of distribution in these normal-hearing subjects. This makes the interpretation of such gaps spurious when values are below 20-30 dB. Speech recognition threshold has the highest degree of test-retest precision of all audiometric tests, and this is probably due to the steep slope of the psychometric function at 50% intelligibility. A more detailed graphic presentation of the 50% point of intersection will bring the reproducibility down to less than 2.5 dB.

Adult↗
PubMed1989

[Hearing loss in children. Diagnostic challenges].

Auditory brain stem response thresholds have been determined in 142 anaesthetized children who were difficult or impossible to assess using conventional behavioural audiometry techniques. Auditory brain stem response was later compared with puretone thresholds in the 2-4 kHz range, and an acceptable auditory brain stem response reliability was demonstrated. Using the auditory brain stem response results as a basis, we analysed some parental and behavioural auditory aspects in order to obtain a reliable diagnosis of hearing at a younger age than hitherto.

Adolescent↗
PubMed1989

Air conduction thresholds and secretory otitis media: a conventional and extra-high frequency audiometric comparison.

A comparison has been made of air conduction threshold changes up to 1 year after myringotomy, aspiration of middle ear fluid, and insertion of ventilation tubes in ten patients with bilateral and 12 with unilateral secretory otitis media (SOM). Pure tone air conduction thresholds have been analyzed in three frequency groups: low frequency (LF; 0.25 0.5, and 1 kHz), high frequency (HF; 2, 4, and 8 kHz), and extra-high frequency (EHF; 10, 12, 14 and 16 kHz). In the LF and HF ranges, significant improvement came during the first 24 hours after intubation, while in the EHF range, threshold lowering occurred gradually over the following 2 months. Possible explanations for these findings are discussed.

Adolescent↗
PubMed1989

Paediatric auditory brainstem response and pure-tone audiometry: threshold comparisons. A study of 142 difficult-to-test children.

Auditory brainstem response (ABR) thresholds have been determined in 142 anaesthetized 'difficult-to-test' children. The stimuli employed were 2-kHz tone bursts. Pneumatic otomicroscopy was carried out prior to the ABR assessment in all cases, and diagnostic myringotomy was performed when there was the slightest suspicion of abnormality. Long-term follow-up pure-tone audiograms were obtained in 56 patients. A comparison was made between ABR and pure-tone thresholds in the 2-4 kHz range both in healthy middle ears and in ears having middle ear effusion (MEE) at the time of ABR measurement. A correction factor for prediction of behavioural threshold from the ABR threshold both in healthy and in MEE ears is proposed.

Adolescent↗
PubMed1989

Low-level 0.5 and 1 kHz auditory brainstem responses. A search for the low-frequency point in the two-point ABR audiogram.

We have compared the auditory brainstem responses (ABRs) to 0.5 and 1 kHz tone burst stimuli with high-pass noise masking in 10 normal-hearing adults. The overall quality of the low-level responses was poor, but a two-point ABR audiogram is feasible by using the summation technique described. The 1 kHz stimulus gave slightly better responses than 0.5 kHz, and a correction factor of 30-40 dB seems necessary. Our data indicate that these low-level, low-frequency responses are frequency-specific.

Adult↗
PubMed1989

Hearing identification in difficult-to-test children. A study of 142 infants and children.

Prior to auditory brainstem response (ABR) threshold determinations in 142 anaesthetized 'difficult-to-test' children, 125 had one or more behavioural auditory tests performed. We used the ABR thresholds as a basis and retrospectively analysed the case records in relation to some parental and behavioural auditory aspects. The accuracy of the parental opinion regarding hearing has been evaluated, and showed a relatively high rate of false-negatives (29%). In contrast, the presence of a hearing loss was correctly identified in 53%. The reliability of one or more standard behavioural auditory tests was poor in children with normal hearing, but in hearing impaired, there was agreement between ABR and behavioural results in more than 70% of cases. Median age at the ABR examination was 32 months. These and other results are discussed in view of the need to minimize diagnostic delay.

Adolescent↗
PubMed1988

Septoplasty and/or submucous resection? 5 years nasal septum operations.

Information obtained from the case-records and completed questionnaires from 478 patients operated in the 5-year-period 1980 through 1984 with either septoplasty or submucous resection (SMR), has been analysed on an average 31 months after surgery. Two hundred (42 per cent) underwent SMR and 278 (58 per cent) septoplasty. Twenty per cent presented for a clinical follow-up examination. Of the 478 patients, 63 per cent were satisfied. More patients were satisfied with the functional results after septoplasty, which also resulted in fewer and smaller perforations than SMR. Septoplasty ought to replace the latter as the routine procedure. 10 per cent had troublesome crusting independent of the technique used. Change in the external shape of the nose is a minor problem for the patients, and was not regarded as an indication for re-operation. Patients with allergic rhinitis may undergo septal surgery on general lines.

Adolescent↗
PubMed1988

Low-frequency auditory brainstem response threshold.

Auditory brainstem thresholds have been determined in 35 non-cooperative, anaesthetized children using a 'two-point audiogram' paradigm. The high-frequency point was found with a 2 kHz tone-burst without masking, and the low-frequency with a 0.5 kHz tone-burst together with 1 kHz high-pass noise masking. Great variability was found in the low-frequency thresholds, and only 3 of 18 ears with normal high-frequency thresholds had low-frequency thresholds below 70 dB nHL. It is concluded that the 0.5 kHz tone-burst with 1 kHz high-pass noise masking is not a reliable method for routine assessment of low-frequency auditory threshold at the brainstem level.

Adolescent↗
PubMed1988

Auditory brainstem responses and extratympanic electrocochleography. A threshold comparison in children.

Electrocochleography (ECoG) and auditory brainstem response (ABR) have been recorded simultaneously in 23 children referred for threshold evaluation. The ECoG electrode is an extratympanic silver ball (Life-Tech) whereas the ABR is recorded with Ag-AgCl surface electrodes. Of the 30 ears investigated according to this protocol, 11 had no response with either technique, and in a further 11 no difference was found between ECoG and ABR thresholds. In the remaining 8 ears, ABR threshold was lower in 6 and the ECoG in 2. We conclude that the extra time needed for cleansing the ear canal and inserting the electrode does not justify the use of ECoG in threshold evaluations, since the ABR alone has the necessary sensitivity.

Adolescent↗