[Speech discrimination with separated signal sources and sound localization with speech stimuli : Learning effects and reproducibility]. / Verstehen im Störschall mit räumlich getrennten Signalquellen und Richtungshören mit Sprachstimuli : Lerneffekte und Reproduzierbarkeit.

BACKGROUND: Binaural hearing enables better speech comprehension in noisy environments and is necessary for acoustic spatial orientation. This study investigates speech discrimination in noise with separated signal sources and measures sound localization. The aim was to study characteristics and reproducibility of two selected measurement techniques which seem to be suitable for description of the aforementioned aspects of binaural hearing. MATERIALS AND METHODS: Speech reception thresholds (SRT) in noise and test-retest reliability were collected from 55 normal-hearing adults for a spatial setup of loudspeakers with angles of ±â€¯45° and ±â€¯90° using the Oldenburg sentence test. The investigations of sound localization were conducted in a semicircle and fullcircle setup (7 and 12 equidistant loudspeakers). RESULTS: SRT (S-45N45: -14.1 dB SNR; S45N-45: -16.4 dB SNR; S0N90: -13.1 dB SNR; S0N-90: -13.4 dB SNR) and test-retest reliability (4 to 6 dB SNR) were collected for speech intelligibility in noise with separated signals. The procedural learning effect for this setup could only be mitigated with 120 training sentences. Significantly smaller SRT values, resulting in better speech discrimination, were found for the test situation of the right compared to the left ear. RMS values could be gathered for sound localization in the semicircle (1,9°) as well as in the fullcircle setup (11,1°). Better results were obtained in the retest of the fullcircle setup. CONCLUSION: When using the Oldenburg sentence test in noise with spatially separated signals, it is mandatory to perform a training session of 120 sentences in order to minimize the procedural learning effect. Ear-specific SRT values for speech discrimination in noise with separated signal sources are required, which is probably due to the right-ear advantage. A training is recommended for sound localization in the fullcircle setup.

[Management of vestibular schwannomas]. / Management des Vestibularisschwannoms.

Vestibular schwannomas are benign neoplasms originating from the Schwann cells of the vestibular vestibular nerve of the vestibulocochlear nerve, and rarely from the pars cochlearis. These are tumors that are in contact with the nerve but do not bind the fibers. Benign neoplasms of the Schwann cells of the auditory and equilibrium nerves can also occur primarily in the inner ear and are referred to as intralabyrinthine schwannomas (ILS). Vestibular schwannomas represent 6-7 % of all intracranial and 90 % of cerebellopontine angle tumors. Bilateral occurrence occurs in < 5 % of cases, and then corresponds to type 2 neurofibromatosis. The first symptom is often a unilateral hearing loss. It may then lead to balance disorders, tinnitus, facial paralysis and other impairments. Diagnosis is audiological, vestibular and imaging. Magnetic resonance imaging currently represents the gold standard. Management chooses between an observational strategy and surgery, depending on tumor size, age, and other factors. The possible access routes offer different advantages and disadvantages; the potential complications include the liquorrhoea. Radiation therapy is possible in special cases, and drug therapies are also being tested. In the rehabilitation of the hearing function, in addition to a CROS or BICROS restoration, the cochlear implant has been used with good success. The impact on quality of life is largely determined by hearing impairment, balance disorders, tinnitus, and possibly headache, which must be considered in patient consultation and long-term care.

Current audiological diagnostics.

Today's audiological functional diagnostics is based on a variety of hearing tests, whose large number takes account of the variety of malfunctions of a complex sensory organ system and the necessity to examine it in a differentiated manner and at any age of life. The objective is to identify nature and origin of the hearing loss and to quantify its extent as far as necessary to dispose of the information needed to initiate the adequate medical (conservative or operational) treatment or the provision with technical hearing aids or prostheses. Moreover, audiometry provides the basis for the assessment of impairment and handicap as well as for the calculation of the degree of disability. In the present overview, the current state of the method inventory available for practical use is described, starting from basic diagnostics over to complex special techniques. The presentation is systematically grouped in subjective procedures, based on psychoacoustic exploration, and objective methods, based on physical measurements: preliminary hearing tests, pure tone threshold, suprathreshold processing of sound intensity, directional hearing, speech understanding in quiet and in noise, dichotic hearing, tympanogram, acoustic reflex, otoacoustic emissions and auditory evoked potentials. Apart from a few still existing gaps, this method inventory covers the whole spectrum of all clinically relevant functional deficits of the auditory system.

The accuracy of objective threshold determination at low frequencies: comparison of different auditory brainstem response (ABR) and auditory steady state response (ASSR) methods.

OBJECTIVE: The hearing threshold at 500 Hz was estimated using five methods which are suitable for the low frequency range: Low-Chirp BERA (LCBERA), Notched-noise BERA (NNBERA), Narrow band CE-Chirp BERA (NBCBERA) and Narrow band CE-Chirp ASSR (NBCASSR) (40/90 Hz). The slope of the discrimination function of each method was used for determination of the most efficient method. The threshold values were compared and the corresponding odds ratios (OR) were calculated. DESIGN: All methods were applied to each subject. Stimulus levels were arranged individually. Response detection was carried out by visual inspection of the records in case of BERA and automatically in case of ASSR. Each individual series of recordings was converted to a dichotomous function indicating whether or not a response was discernible and a continuous method-specific discrimination function was constructed. This function was realised by a Boltzmann function whose slope in the inflection point serves as quality measure. Additionally, an OR evaluation was carried out in order to validate the significance of results. STUDY SAMPLE: Twenty five normal hearing adults (aged 18-30 years) were tested. RESULTS: LCBERA proved to have the highest reliability according to the slope of the Boltzmann function, the comparison of threshold values and OR. CONCLUSIONS: The LCBERA is recommended for use in routine clinical practice.

[Current Audiological Diagnostics]. / Aktuelle audiologische Diagnostik.

Today's audiological functional diagnostics is based on a stock of hearing tests, whose large number takes account of the variety of malfunctions of a complex sensory organ system and the necessity to examine it in a differentiated manner and at any age of life. The objective is to identify nature and origin of the hearing loss and to quantify its extent as far as necessary to dispose of the information needed to initiate the adequate medical (conservative or operational) treatment or the provision with technical hearing aids or prostheses. Moreover, audiometry provides the basis for the assessment of impairment and handicap and for the calculation of the degree of disability. In the present overview, the current state of the method inventory available for practical use is described, starting from basic diagnostics over to complex special techniques. The presentation is systematically grouped in subjective procedures, based on psychoacoustic exploration, and objective methods, based on physical measurements: preliminary hearing tests, pure tone threshold, suprathreshold processing of sound intensity, directional hearing, speech understanding in quiet and in noise, dichotic hearing, tympanogram, acoustic reflex, otoacoustic emissions and auditory evoked potentials. Apart from a few still existing gaps, this method inventory covers the whole spectrum of all clinically relevant functional deficits of the auditory system.

Evaluation of optimal masking levels in place-specific low-frequency chirp-evoked auditory brainstem responses.

The aim of the study is the experimental determination of the optimal required masking level for a given stimulus level when using a band limited "low-frequency chirp" in order to improve frequency and place specificity of auditory brainstem responses (ABRs). A low-frequency chirp (100-850 Hz) at stimulation levels between 40 and 80 dB normalized hearing level was presented to 12 normal hearing subjects. During presentation of each stimulus, the level of a high-pass noise with a low cutoff frequency of 1100 Hz was varied between 0 and 25 dB signal-to-noise ratio (SNR) by using 5 dB steps (at 0 dB SNR the same level of both the chirp and the masker in dB sound pressure level was presented). Measurements without masking were used as a reference. In all masking conditions, the latency of wave V was significantly increased compared to unmasked ABRs. The amplitude of wave V decreased when reaching the effective and therefore optimal masking level. Accordingly, in order to ensure place specificity of the ABR, ipsilateral masking is essential. At lower stimulus levels the SNR can be substantially increased (i.e., the masker level decreased) without loss of place specificity.

Therapeutic approach to chickenpox in children and adults--our experience.

INTRODUCTION: Chickenpox is highly contagious childhood disease which occurs as a result of varicella-zoster virus primary infection. Symptomatic therapy is usually adequate for chickenpox, but in some cases it requires combinations of antiviral drugs and antibiotics. OBJECTIVES: To present our expirience with chickenpox therapy in children and adult patients. MATERIAL AND METHODS: Study included 120 randomly chosen patients, 60 adults and 60 children, with confirmed chickenpox infection, hospitalised at Clinic for infectious diseases in Sarajevo. Observed period was 1st January 2005. to 30th June 2011. We compared used therapy and outcome of disease. RESULTS: We had 333 patients with confirmed chickenpox in mentioned period. Male sex prevailed. Antiviral (acyclovir) therapy was initiated in 8(13.5%) adults and 16(27%) children. Most frequently used antibiotic was Co-Amoxiclav in a group of adults and Ceftriaxone in a group of children. DISCUSSION AND CONCLUSION: We use different terapeutical approaches to chickenpox according to the severity of the clinical picture and the existence of underlying diseases. Symptomatic treatment is indicated in all immunocompetent patients with no signs of complications. Use of corticosteroids remains open dillemma. Our therapeutical approcach followed by actual guidelines proved to be usefull. No death cases were recorded in these

Varicella Pneumonia in a 39-year-old Female in Third Trimester Twin Pregnancy.

CONFLICT OF INTEREST: none declared. INTRODUCTION: Chickenpox is disease caused by varicella-zoster virus (VZV), with possibly devastated consequences during pregnancy, for mother and neonate. Pneumonia is most common complication in pregnancy with very high mortality. CASE REPORT: A 39-year-old female in third trimester twin pregnancy, referred to Clinic for infectious diseases in Sarajevo, with five days history of illness. Before the admission her condition get worse, with fatigue, exhaustion, and shortness of breath. In a first three days patient was febrile, tachydispnoic and ortopnoic. We started therapy with acyclovir and antibiotic. After four days we had detoriation in patient's condition. Chest X-ray revealed infiltrative shadows in basal parts of lung. Antimicrobial therapy was changed and corticosteroids were associated. Significant improvement was noticed after five days of therapy. CONCLUSION: Varicella pneumonia during third trimester may have serious consequences for mother and child, with possible fatal outcome.