Biomedical subjects

Ad F M Snik

Publications and source records attributed to Ad F M Snik.

26 records · Page 2Linked to original sources

PubMed2003

Bone-anchored hearing aids in unilateral inner ear deafness.

In nine patients with unilateral deafness and normal hearing in the contralateral ear, measurements of sound localization and speech perception were obtained before intervention, with a conventional contralateral routing of sound (CROS) hearing aid and later with a bone-anchored hearing aid (BAHA) implanted in the deaf ear. Sound localization did not show any differences between the three conditions. Speech perception using short, everyday sentences showed a reduction in the head-shadow effect of 2 dB for both the conventional CROS hearing aid and the BAHA in comparison to the unaided condition. Patients' real-life experiences of the three conditions were evaluated using the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire. The results showed a significant benefit with the BAHA in situations involving background noise and reverberation and a reduced aversion to loud sounds in comparison to the unaided and conventional CROS conditions.

Audiometry, Speech↗

PubMed2003

Comparison of different speech coding strategies using a disability-based inventory and speech perception tests in quiet and in noise.

OBJECTIVE: Intraindividual comparison of two cochlear implant speech coding strategies implemented in the Nucleus 24M system (SPEAK versus ACE). Reasons for subjective preference were evaluated using a combination of speech perception scores and a disability-based inventory. STUDY DESIGN: Cross-over study with two groups of cochlear implant subjects, assigned to first receive ACE or SPEAK strategy. SETTING: Cochlear implant program. SUBJECTS: Twelve postlingually deaf adults using a Nucleus 24M cochlear implant system. INTERVENTION: Subjects consecutively used the two different speech coding strategies and completed speech perception tests in quiet and in noise and a disability-based inventory (Abbreviated Profile of Hearing Aid Benefit). MAIN OUTCOME MEASURES: Individual differences between the two different speech coding strategies and the relation with subjective strategy preference. RESULTS: The ACE strategy produced somewhat better speech recognition scores in quiet and in noise, although the difference in the scores in noise did not reach the 95% level of significance. The first coding strategy chosen did not affect the results or subjective preference. Preference according to the APHAB results were not a priori in conformity with the speech recognition scores. CONCLUSION: Most subjects preferred the ACE strategy. Subjective preference was in agreement with the APHAB results in three subjects, in agreement with speech recognition in two subjects, and in agreement with both in seven subjects. The present results support the use of both speech recognition tests and questionnaires to evaluate different speech coding strategies.

Adult↗

PubMed2003

Hearing deficits in young adults who had a history of otitis media in childhood: use of personal stereos had no effect on hearing.

OBJECTIVE: To test the hypothesis proposed in a recent French study that a history of recurrent otitis media (OM) in childhood increases susceptibility to hearing loss from frequent exposure to a personal stereo (PS) during development to early adulthood. METHODS: A subcohort of 358 young adults selected from a historic cohort study, all 18 years old and with a well-documented OM history (secretory and acute), provided data on the sound level and length of exposure to PSs. Four contrasting groups were formed: those with the highest or lowest PS exposure combined with a positive or negative history of OM (n = 238). The main outcome measure was hearing thresholds from pure-tone audiometry (0.5-8 kHz). RESULTS: Young adults with a history of recurrent OM in childhood did not show greater susceptibility to hearing loss from PS use than their peers without a history of OM. However, a history of recurrent OM was associated with significant mean air-conduction hearing loss of 4 dB and a mean bone-conduction hearing loss of 2 dB compared with the participants without a history of OM (Fig 1). CONCLUSIONS: Recurrent OM in childhood may have an irreversible effect on the middle ear and the cochlea and may lead to hearing deficits in later life. No interaction with PS exposure is seen.

Acoustic Impedance Tests↗

PubMed2003

Assessment of auditory processing in 6-year-old language-impaired children.

The performance of a group of twenty 6-year-old children with specific language impairment (SLI) on several behavioural auditory tests was compared to that of a group of twenty age-matched control children. The auditory test battery used in this study consisted of the following tests: a speech-in-noise test, a filtered speech test, a binaural fusion test, a frequency pattern test, a duration pattern test, a temporal integration test, an auditory word discrimination test, an auditory synthesis test, an auditory closure test and a number recall test. Our results show that the SLI children obtained scores on almost all tests that were significantly lower than those of the control group. Many of the basic auditory processing measures in our test battery correlated significantly with receptive and language scores, suggesting a (causal) relationship between auditory processing and language proficiency. Results from discriminant function analyses do not warrant deleting one or more tests from the test battery yet (with the exception of the auditory synthesis test and the temporal integration test, for which we did not find significant group effects). At present, we are conducting experiments with older (SLI and control) children and adults to find whether the significant performance deficits of the SLI children are also found in older SLI children, and to determine the influence of maturational effects on these auditory tests.

Case-Control Studies↗

PubMed2002

The bone-anchored hearing aid in patients with a unilateral air-bone gap.

OBJECTIVES: To study the benefit of the application of a bone-anchored hearing aid in patients with a unilateral air-bone gap. STUDY DESIGN: Prospective evaluation in eight patients. METHODS: Binaural hearing was assessed in the sound field by comparing aided and unaided scores obtained with a sound localization test and a speech recognition in noise test with spatially separated sound and noise sources. SETTING: Tertiary referral center. PATIENTS: The patients had subnormal hearing and unilateral conductive hearing loss. RESULTS: Sound localization improved significantly in the six patients with acquired hearing loss. The binaural advantage, studied with speech-in-noise tests with spatially separated speech and noise sources, proved to be comparable with that in a control group of subjects with normal hearing when they were listening monaurally versus binaurally. For one of the two patients with unilateral congenital conductive hearing loss, the results were ambiguous. This patient's age at the time of surgery was high: 40 years (the other patient was 19 years old at the time of surgery). This might have played a role. CONCLUSION: If reconstructive surgery is not possible (e.g., in a patient with a chronically draining ear or a severe congenital malformation), a bone-anchored hearing aid is an option to reestablish binaural hearing. The results reported herein suggest that, at least for patients with acquired hearing loss, the bone-anchored hearing aid is an effective treatment of unilateral conductive hearing loss.

Acoustic Stimulation↗

PubMed2002

Evaluation of cochlear implant benefit with auditory cortical evoked potentials.

Endogenous P300 and exogenous slow vertex potentials were obtained with tone and speech stimuli in a group of five children using a cochlear implant (CI) with poor speech recognition (group A) and compared with those from another group of five children using a CI with good speech recognition (group B). The responses were also compared to those of children with normal hearing (n= 14) and a group of adult CI users (n=9). N1 and P2 latencies of CI group A and group B were prolonged compared to those of normally-hearing children. In group A, P300 was present when contrasts with tone stimuli were used. When speech stimuli were used, P300 potentials were absent or delayed. P300 potentials obtained in group B were no different from those obtained in normally-hearing children. It is suggested that the poor results evoked with speech stimuli in contrast to those evoked with pure-tone stimuli in group A are due to the immaturity of (sub) cortical generators associated with acoustical and phonetic processing. In contrast to the children in group B, all children in group A suffered from congenital deafness.

Adolescent↗

PubMedDate not supplied

Candidacy for the bone-anchored hearing aid.

The BAHA (bone-anchored hearing aid) is a bone conduction hearing aid with percutaneous transmission of sound vibrations to the skull. The device has been thoroughly evaluated by various implant groups. These studies showed that, in audiological terms, the BAHA is superior to conventional bone conduction devices. In comparison with air conduction devices, the results are ambiguous. However, a positive effect is found with respect to aural discharge. The most powerful BAHA can be applied to patients with a sensorineural hearing loss component of up to 60 dB HL. It was shown that bilateral BAHA application leads to binaural sound processing. Preliminary results on the application of the BAHA in patients with unilateral conductive hearing loss suggest that stereophonic hearing can be re-established. The application of the BAHA as a transcranial CROS (contralateral routing of signal) device in unilateral deafness minimizes head shadow effects.

Auditory Threshold↗

PubMedDate not supplied

Signal-to-noise ratios of the auditory steady-state response from fifty-five EEG derivations in adults.

The Auditory Steady-State Response (ASSR) was recorded in 20 awake adults with normal hearing on ten EEG channels simultaneously to find derivations with the best signal-to-noise ratios (SNRs). Stimuli were 20% frequency modulated tones of 0.5 and 2 kHz at 20 dB SL, 100% amplitude modulated at 90 or 94 Hz, and presented one at a time to one ear. ASSR recordings using a set of at least three channels improved SNRs significantly by an average of between 6% (500 Hz right ear) to 118% (2 kHz right ear) above the SNRs from the conventional channels. Assuming that the recording time was proportional to 1/(SNR)2, this translates into a recording time of 89% (500 Hz right ear) to 21% (2 kHz right ear) of that for conventional single-channel recording. The three channels comprised the electrode positions inion, right mastoid, and left mastoid. All three electrode positions were referenced to Cz. Adding a fourth channel (Pz-Cz) increases the number of participants with significant responses from the 500 Hz right ear stimulus from 13 to 17. Electrode position F4 and other commonly used positions such as the forehead and right earlobe made significantly less contribution to test efficiency.

Acoustic Stimulation↗