Biomedical subjects

E A Mylanus

Publications and source records attributed to E A Mylanus.

24 records · Page 2Linked to original sources

PubMed1994

Audiologic results for the bone-anchored hearing aid HC220.

Twenty-six patients with severe mixed hearing loss (PTA range 57 to 108 dB HL) were fitted with the "super-bass" bone-anchored hearing aid (BAHA) HC220 and divided into two groups. Group I contained 19 patients who previously used a conventional bone conduction hearing aid that had resulted in serious complaints. Group II contained 7 patients who had previously used an air conduction hearing aid that could no longer be used because of recurrent otorrhoea. Sound field speech audiometry for the patients in Group I revealed that for 7 patients the maximum phoneme score did not change, but that it improved for 12 patients with the HC220, compared with their conventional bone conduction hearing aid. In Group II, the maximum phoneme score improved for 3 patients, worsened for 3 patients and did not change for 1 patient with the HC220, compared with their air conduction hearing aid. Speech recognition in noise was difficult for most of the patients regardless of group. However, results were obtained from 10 patients, and 7 improved significantly with the HC220 compared with their previous aid. Overall, speech recognition with the HC220 was comparable with or better than a conventional bone conduction hearing aid; however, compared with an air conduction hearing aid the results were ambiguous.

Adult↗

PubMed1994

Audiological results of the bone-anchored hearing aid HC200: multicenter results.

Sixty-two patients with conductive or mixed hearing loss (average bone conduction threshold at 0.5, 1, and 2 kHz ranged from 1 to 44 dB hearing level) were fitted with a bone-anchored hearing aid (BAHA type HC200). Previously, 52 of them had used a conventional bone conduction hearing aid (CBHA) and 10 of them an air conduction hearing aid (ACHA). Audiological tests were conducted to compare the patients' performance with the BAHA to that with their previous conventional hearing aid. In the speech recognition in quiet test, only 5 patients in the CBHA group improved significantly: the majority had 100% scores with both hearing aids. In the speech recognition in noise test, 28 patients improved significantly. The mean improvement in the signal to noise ratio (S/N) in the CBHA group was -2.3 +/- 2.4 dB. That none of the patients in the CBHA group performed worse with the BAHA led us to the conclusion that the BAHA is superior to the CBHA. None of the patients in the ACHA group achieved a better speech recognition in quiet score using the BAHA. On average, there was no significant improvement in the S/N ratio in the ACHA group, although in 6 patients the S/N ratio improved significantly, and in 1 patient it worsened significantly. From the whole group, the performance of only 2 patients, both in the ACHA group, was significantly worse with the BAHA on one of the speech recognition tests.

Adolescent↗

PubMed1994

Influence of the thickness of the skin and subcutaneous tissue covering the mastoid on bone-conduction thresholds obtained transcutaneously versus percutaneously.

Percutaneous and transcutaneous bone-conduction thresholds were obtained at 0.25, 0.5, 1, 2, and 4 kHz in 57 patients who were fitted with the Bone Anchored Hearing Aid (BAHA). Additionally, the thickness of the skin and subcutaneous tissue covering the mastoid was determined. No relation was found between the thickness of the skin and subcutaneous tissue, and the improvement in bone-conduction thresholds at any of the frequencies, i.e. thresholds obtained percutaneously minus transcutaneously. The improvement (or deterioration) in speech recognition with the BAHA in a subgroup of patients who had previously used a (conventional) transcutaneous bone-conduction hearing aid was not related to the thickness of the skin and subcutaneous tissue layers. Therefore, the thickness of the skin and subcutaneous tissue layers measured pre-operatively cannot be used as a predictor of successful fitting with a BAHA.

Adolescent↗

PubMed1994

Speech recognition with the bone-anchored hearing aid determined objectively and subjectively.

Some patients with a bone-conduction hearing aid experience serious problems such as skin irritation or headaches and inconsistency in the sound quality due to shifting of the transducer over the mastoid. The Bone Anchored Hearing Aid (BAHA) provides direct bone-conduction and therefore evades these problems. Results of 58 patients fitted with either the head level BAHA HC200 or the more powerful HC220 were available for evaluation. Speech recognition-in-quite and in-noise tests were performed in order to make a comparison between the patients' performance with their individually adapted BAHA and their previous hearing aid. Furthermore, all the patients filled out a questionnaire, involving questions on speech recognition-in-quite and in-noisy surroundings. Individual comparisons of the audiological and questionnaire results in the subgroup of patients who had used a bone-conduction hearing aid showed that the results with the BAHA were comparable with or significantly better than those with the previous bone-conduction hearing aid. The results in the patients who had previously used an air-conduction hearing aid were ambiguous.

Adolescent↗

PubMedDate not supplied

Percutaneous titanium implantation in the skull for the bone-anchored hearing aid.

In the 1980s, a new type of bone conduction hearing aid was developed in Göteborg, Sweden. With this new bone-anchored hearing aid (BAHA) system, sound waves are transmitted directly to the skull by means of a titanium screw implanted into the skull. The advantages and disadvantages of the conventional hearing aid and the BAHA are described here. In the 25 patients presented, all the percutaneous implants remained firmly anchored in the skull. One screw was lost through trauma. The scores on the speech recognition-in-noise and the speech recognition-in-quiet tests were significantly higher in 64% and 32% of the patients with a BAHA, respectively.

Adolescent↗

PubMedDate not supplied

Audiometric evaluation of bilaterally fitted bone-anchored hearing aids.

Bilateral fittings of bone-anchored hearing aids (BAHA) were evaluated in 25 patients with at least 3 months experience with using two BAHAs. For all patients, air conduction hearing aids were contraindicated due to either recurrent otorrhoea or otitis externa (19 cases) or to congenital aural atresia (six cases). Candidacy for bilateral fitting was primarily based on symmetry of bone conduction thresholds. For all patients, measurements comprised sound localisation, speech recognition in quiet and in noise. In addition, in a subgroup of nine patients, release from masking for pure-tone stimuli in noise with interaural phase differences (binaural masking level difference. BMLD) was measured. The percentage of correct localisation judgments with 500-Hz and 2-kHz noise bursts increased significantly (p<0.01) from 22.2 per cent and 24.3 per cent for unilateral fittings to 41.8 per cent and 45.3 per cent for bilateral fittings, respectively. With unilateral fittings sound localisation judgments appeared to be strongly biased to the ipsilateral BAHA side. whereas with bilateral fittings, judgments were far more symmetrical. The speech reception threshold for sentences in quiet was significantly (p<0.01) better for the bilateral fittings compared to the unilateral fittings: 37.5 dBA versus 41.7 dBA. Speech recognition in noise was measured with the speech signal presented in front of the listener and a 65-dBA masking noise at either +90 degrees or -90 degrees azimuth. For noise presented at the ipsilateral side of the first fitted BAHA, the signal-to-noise ratio was significantly reduced (p<0.01) from -0.7 dB for the unilateral fitting to -4.0 dB for the bilateral fitting. The speech reception threshold in noise was not significantly different (p>0.05) for unilateral and bilateral fittings when the noise was presented at the contralateral side of the first fitted BAHA. The results for the six patients with congenital atresia are comparable with those for the other patients. So, directional hearing and speech recognition in noise improve significantly with a second BAHA. The BMLD measurements showed a significant (p<0.01) release from masking of 6.1, 6.0 and 6.6 dB for 125-Hz, 250-Hz and 500-Hz stimuli, respectively. The BMLD effect of 4.1 dB at 1,000 Hz was not significant at the 5 per cent level. The positive results with the bilateral fittings in quiet can be ascribed to increased stimulus levels due to diotic summation of signals from either side. The results for localisation, speech recognition in noise and BMLD measurements indicate that bilaterally fitted BAHAs do indeed (to some extent) result in binaural hearing.

Adolescent↗