Twin study of neonatal transient-evoked otoacoustic emissions.

Our knowledge of which physiological mechanisms shape transient evoked otoacoustic emissions (TEOAEs) is incomplete, although thousands of TEOAEs are recorded each day as part of universal newborn hearing-screening (UNHS). TEOAE heritability may explain some of the large TEOAE variability observed in neonates, and give insights into the TEOAE generators and modulators, and why TEOAEs are generally larger in females and right ears. The aim was to estimate TEOAE heritability and describe ear and sex effects in a consecutive subset of all twins that passed UNHS at the same occasion at two hospitals during a six-year period (more than 30 000 neonates screened in total).

Changes in cochlear function related to acoustic stimulation of cervical vestibular evoked myogenic potential stimulation.

Evaluation of cervical evoked myogenic potentials (c-VEMP) is commonly applied in clinical investigations of patients with suspected neurotological symptoms. Short intense acoustic stimulation of peak levels close to 130 dB SPL is required to elicit the responses. A recent publication on bilateral significant sensorineural hearing loss related to extensive VEMP stimulation motivates evaluations of immediate effects on hearing acuity related to the intense acoustic stimulation required to elicit c-VEMP responses.

Corneal-Reflection Eye-Tracking Technique for the Assessment of Horizontal Sound Localization Accuracy from 6 Months of Age.

Objectives: The evaluation of sound localization accuracy (SLA) requires precise behavioral responses from the listener. Such responses are not always possible to elicit in infants and young children, and procedures for the assessment of SLA are time consuming. The aim of this study was to develop a fast, valid, and objective method for the assessment of SLA from 6 months of age.

Academic Achievement of University Students with Dyslexia.

Broadened recruitment to higher education is on the agenda in many countries, and it is also widely recognized that the number of dyslexic students entering higher education is increasing. In Sweden, as in many other European countries, higher education institutions are required to accommodate students with dyslexia. The present study focuses on the study outcome for 50 students with diagnosed dyslexia, mainly in teacher education and nurses' training, at three universities in Northern Sweden.

Tinnitus and other auditory problems - occupational noise exposure below risk limits may cause inner ear dysfunction.

The aim of the investigation was to study if dysfunctions associated to the cochlea or its regulatory system can be found, and possibly explain hearing problems in subjects with normal or near-normal audiograms. The design was a prospective study of subjects recruited from the general population. The included subjects were persons with auditory problems who had normal, or near-normal, pure tone hearing thresholds, who could be included in one of three subgroups: teachers, Education; people working with music, Music; and people with moderate or negligible noise exposure, Other.

Analysis of click-evoked auditory brainstem responses using time domain cross-correlations between interleaved responses.

Objectives: The rapidly evolving field of early diagnostics after the introduction of newborn hearing screening requires rapid, valid, and objective methods, which have to be thoroughly evaluated in adults before use in infants. The aim was to study cross-correlation analysis of interleaved auditory brainstem responses (ABRs) in a wide dynamic range in normal-hearing adults. Off-line analysis allowed for comparison with psychoacoustical click threshold (PCT), pure-tone threshold, and determination of ABR input/output function.

The efficacy of N-acetylcysteine to protect the human cochlea from subclinical hearing loss caused by impulse noise: a controlled trial.

In military outdoor shooting training, with safety measures enforced, the risk of a permanent, noise-induced hearing loss is very small. But urban warfare training performed indoors, with reflections from walls, might increase the risk. A question is whether antioxidants can reduce the negative effects of noise on human hearing as it does on research animals.

Successful and unsuccessful users of bilateral amplification: differences and similarities in binaural performance.

Bilateral amplification seems to be the best solution for bilaterally hearing-impaired persons. Nevertheless, some individuals are unsuccessful with this strategy. The goals of the present study were to develop tests to improve the diagnostic test battery before rehabilitation of hearing-impaired persons with bilateral or unilateral amplification, and to evaluate the tests with normally-hearing subjects and with two groups of hearing-impaired persons.

Evaluation of the usefulness of a silicone tube connected to a microphone in monitoring noise levels induced by drilling during mastoidectomy and cochleostomy.

Conclusion: The use of a silicone tube and a microphone enables peroperative noise recordings in cadavers and should be safe to apply in vivo. Our preliminary data indicate that noise levels during inner ear surgery reach levels that can cause noise-induced hearing loss. Our method is easily performed and enables future uncomplicated and safe noise recordings and we suggest future application in vivo to expand knowledge regarding peroperative noise levels.

Objectively measured and subjectively perceived distortion in nonlinear systems.

A method for measuring nonlinear distortion, which is applicable to almost any transmission system and which can use any input signal as a test signal, is proposed. The method exploits the fact that a pair of signals, generated to form the real and imaginary parts of the analytical signal corresponding to the input signal to a system, lose their property of being a Hilbert pair after being passed through a nonlinear system. The method was tested by measuring 12 different hearing aid compression systems.

The effect of audibility, signal-to-noise ratio, and temporal speech cues on the benefit from fast-acting compression in modulated noise.

The objective of the experiment was to investigate three aspects that might contribute to the benefit of fast-acting compression seen in normal-hearing listeners. Six normal-hearing listeners were tested with speech recognition in a fully modulated noise (FUM) either through a fast-acting compressor or through linear amplification. In the first experiment, three different presentation levels of the FUM noise (15, 30, and 45 dB SL) were tested.

Semantic and phonological skills in predicting reading development: from 3-16 years of age.

The present longitudinal study investigated the relationship between pre-school semantic skills (vocabulary, comprehension and sentence construction), phonological awareness and later word decoding and reading comprehension skills. More than 200 Danish children were followed from a speech therapist screening at the age of three, through a phonological group screening at six, word decoding tests in Grade 2, sentence reading tests in Grades 3, 4, and 6, and to a text reading test in Grade 9 (age 16). The predictor variables consisted of both standardized test results, professional ratings, and a factor of interest in books.

The effect of presentation level and compression characteristics on sentence recognition in modulated noise.

The effect of fast-acting compression on speech recognition in fully modulated (FUM) noise in listeners with normal and impaired hearing was investigated in two experiments We wanted to determine the relationships between the benefit from compression and some audiological factors. Furthermore, the sensitivity to changes in compression parameters was also evaluated. The results showed that two-thirds of the listeners performed worse with fast-acting compression than with linear processing.

Dose and time-dependent protection of the antioxidant N-L-acetylcysteine against impulse noise trauma.

Noise-induced hearing loss is one of the most common causes of hearing disability, and at present there is no effective biological protection or cure. Firearms and some industrial equipment can generate very high levels of impulse noise, which is known to cause sensorineural hearing loss. It has been shown that antioxidants such as N-L-acetylcysteine (NAC) can protect the inner ear from oxidative damage.