[Objective measures for setting the processors of cochlear implant systems : Use of discrimination functions and consideration of electrode profiles]. / Objektive Maße bei der Anpassung der Prozessoren von Cochleaimplantatsystemen : Nutzung von Diskriminationsfunktionen und Betrachtung von Elektrodenprofilen.

BACKGROUND: When setting the electrical stimulation level of cochlear implants during individual adjustment of the speech processor, especially in children, objective measures such as intracochlearly measured electrically evoked compound action potentials (eCAP) and intraoperative observation of electrically elicited stapedial reflexes (eSR) are indispensable. The benefit of these objective measures is based on the correlation between the derived response thresholds and psychometric data. MATERIALS AND METHODS: The amplitude growth functions of eCAPs were measured intraoperatively for all electrodes in 30 ears of adult patients. The stimulus-dependent incidence of observable eSRs was recorded for all electrodes in 16 ears of adult patients. For evaluation of the data, new algorithms were applied which allowed the determination of thresholds without intervention of the investigator. Essential features were the conversion of observations into binary variables, and the consideration of logistic discrimination functions and their exceedance of a numeric threshold criterion. RESULTS: Regarding the eCAP data, closer and significant correlations are observed between objective thresholds and psychometric measures in comparison to conventional procedures. Profiles are more efficient than pooled data. Significant correlations are also observed for eSR thresholds, albeit to a lesser extent and without an evident difference between profiles and pooled data. CONCLUSION: Considering the by no means consistent international literature, the results illustrate the need for a consistent definition of response thresholds and the consideration of electrode profiles.

[The Heidelberg CI database module : Quality control in hearing restoration with cochlear implants]. / Das Heidelberger CI­Datenbankmodul : Qualitätssicherung in der Cochleaimplantatversorgung.

BACKGROUND: Cochlear implants (CI) have been established as the therapy of choice for functional deafness. The number of CI-rehabilitated patients is continuously growing. The resulting data can provide important information for physicians, health insurance companies, and scientists. Assessment and structuring of data becomes more feasible with the application of modern database systems. MATERIALS AND METHODS: In collaboration with Innoforce Est., Liechtenstein, the authors developed a database module for the specific needs of CI patients. Data of 100 patients were included and evaluated. The main features of the module and an example data analysis are presented. RESULTS: Analysis of data from these 100 patients reveals 50 men and 50 women aged between 1 and 87 years, with a maximum value in the 51-60-years age group. More than 50% of the patients were also severely hearing impaired in the contralateral ear and fitted the CI indication criteria. Functional deafness in the ear subsequently fitted with CI in most of the patients had arisen more than 20 years previously. Preoperative diagnostic electrical stimulation of the cochlear nerve was positive in 67 patients. All 100 patients perceived auditory sensations with the CI. CONCLUSION: The presented patient cohort is representative of patients at the Department of Otorhinolaryngology, University of Heidelberg Medical Center, Germany, and the demographic distribution is in accordance with the literature. The state of the contralateral ear, often also fitting the CI indication, is not surprising, as cochlear implantation is a comparatively new procedure. Preoperative electrical stimulation turned out not to be significant by itself. The hearing results and overview of complications were easy to calculate in comparison to a pure data storage system such as i.s.h.med.

[The Freiburg speech intelligibility test : A pillar of speech audiometry in German-speaking countries]. / Der Freiburger Sprachtest : Eine Säule der Sprachaudiometrie im deutschsprachigen Raum.

The Freiburg speech intelligibility test according to DIN 45621 was introduced around 60 years ago. For decades, and still today, the Freiburg test has been a standard whose relevance extends far beyond pure audiometry. It is used primarily to determine the speech perception threshold (based on two-digit numbers) and the ability to discriminate speech at suprathreshold presentation levels (based on monosyllabic nouns). Moreover, it is a measure of the degree of disability, the requirement for and success of technical hearing aids (auxiliaries directives), and the compensation for disability and handicap (Königstein recommendation). In differential audiological diagnostics, the Freiburg test contributes to the distinction between low- and high-frequency hearing loss, as well as to identification of conductive, sensory, neural, and central disorders. Currently, the phonemic and perceptual balance of the monosyllabic test lists is subject to critical discussions. Obvious deficiencies exist for testing speech recognition in noise. In this respect, alternatives such as sentence or rhyme tests in closed-answer inventories are discussed.

[The impact of cochlear implants on the quality of life of patients with single-sided deafness]. / Der Einfluss der CI-Versorgung von einseitig tauben Patienten auf die Lebensqualität.

BACKGROUND: Unilaterally deaf patients are increasingly supplied with a cochlear implant (CI). In the present study the change in quality of life following implantation was investigated. PATIENTS AND METHODS: The study comprised 20 postlingual CI recipients with single-sided deafness, who were divided into two groups: "normal hearing" (group 1) and "moderate impairment" (group 2) contralaterally. Their quality of life was determined using four standardized questionnaires (NCIQ, HPS, APHAB, HHIE) and a visual analogue scale. RESULTS: With the exception of the sensation of loud everyday sounds (APHAB AV scale) reported by patients from group 2, all study participants benefited significantly from the implantation. DISCUSSION: The problems caused by the aversiveness of loud everyday sounds can be explained by the enhanced transmission of high frequencies and the associated unfamiliar sensations by the CI system. The effects of deafness duration and response shift remain to be investigated. CONCLUSION: Cochlear implantation for unilaterally deaf patients was found to be a legitimate and meaningful rehabilitation measure.

[Objective diagnostic methods in pediatric audiology]. / Objektive audiologische Diagnostik im Kindesalter.

Objective methods based on the measurement of otoacoustic emissions (OAE) and auditory evoked potentials (AEP) are indispensable in pediatric audiology especially for the early detection and therapy of congenital hearing impairment. The correct and efficient use requires knowledge and skills which are beyond the basic equipment of many users and require continuous updating. In the present review many aspects relevant for the safe handling of the methods and interpretation of the results are addressed. The presentation does not focus on the methods themselves but on the core problem of the practical daily routine, namely the qualitative and quantitative description of hearing loss in terms of its extent, the frequency range affected and the identity with respect to the type and site of the lesion. The certainty of the diagnosis can be optimized by observing few and simple rules. Central importance is attached to the thorough discussion of the interrelated parameters residual noise, signal-to-noise ratio and reproducibility in order to promote their correct use. Further subjects of this article are the recognition of pitfalls, the description of new developments, such as chirp and auditory steady-state responses (ASSR) and finally the consideration of the extraordinarily important aspect of maturation.

[Evaluation of the Freiburg monosyllabic speech test in background noise]. / Evaluation des Freiburger Einsilbertests im Störschall.

BACKGROUND: The Freiburg speech test has been the gold standard in speech audiometry in Germany for many years. Previously, however, this test had not been evaluated in assessing the effectiveness of a hearing aid in background noise. Furthermore, the validity of particular word lists used in the test has been questioned repeatedly in the past, due to a suspected higher variation within these lists as compared to the other word list used. PATIENTS AND METHODS: In this prospective study, two groups of subjects [normal hearing control subjects and patients with SNHL (sensorineural hearing loss) that had been fitted with hearing aid] were examined. In a first group, 113 control subjects with normal age- and gender-related pure tone thresholds were assessed by means of the Freiburg monosyllabic test under free-field conditions at 65 dB. The second group comprised 104 patients that had been fitted with hearing aids at least 3 months previously to treat their SNHL. Members of the SNHL group were assessed by means of the Freiburg monosyllabic test both with and without hearing aids, and in the presence or absence of background noise (CCITT-noise; 65/60 dB signal-noise ratio, in accordance with the Comité Consultatif International Téléphonique et Télégraphique), under free-field conditions at 65 dB. RESULTS: The first (control) group exhibited no gender-related differences in the Freiburg test results. In a few instances, inter-individual variability of responses was observed, although the reasons for this remain to be clarified. Within the second (patient) group, the Freiburg test results under the four different measurement conditions differed significantly from each other (p>0.05). This group exhibited a high degree of inter-individual variability between responses. In light of this, no significant differences in outcome could be assigned to the different word lists employed in the Freiburg speech test. CONCLUSION: The Freiburg monosyllabic test is able to assess the extent of hearing loss, as well as the effectiveness of a fitted hearing aid, in the presence or absence of background-noise (CCITT-noise). The present study could not evidence statistically significant differences in outcome when using the different word lists in this test battery.

[Objective hearing tests in pediatric audiology: AGERA recommendations for follow-up diagnosis in infants that fail newborn hearing screening tests]. / Empfehlungen der AGERA zum Einsatz objektiver Hörprüfmethoden im Rahmen der pädaudiologischen Konfirmationsdiagnostik (Follow-up) nach nicht bestandenem Neugeborenen-Hörscreening.

This paper presents the recommendations compiled by the German Electric Response Audiometry Working Group (Arbeitsgruppe Elektrische Reaktions-Audiometrie, AGERA) and the Association of German Audiologists and Neuro-otologists (Arbeitsgemeinschaft Deutschsprachiger Audiologen und Neurootologen, ADANO) for infants that fail newborn hearing screening (NHS) tests. Outlined are procedures for follow-up diagnosis using objective hearing tests to rule out or confirm a therapeutically relevant auditory defect and assessment of the severity thereof.

Plant U-box armadillo repeat proteins AtPUB18 and AtPUB19 are involved in salt inhibition of germination in Arabidopsis.

Plant U-box armadillo repeat (PUB-ARM) proteins represent a type of E3 ubiquitin ligase. PUB-ARM proteins have various functions in plant development, plant defence and plant stress responses. The so far uncharacterised PUB-ARM proteins AtPUB18 and AtPUB19 are highly homologous to each other and regulated on the transcript level by ABA and NaCl. To investigate their physiological function, we isolated and characterised two Arabidopsis mutants and named them pub18-1 and pub19-1. However, these single mutants did not show any ABA- or salt-dependent phenotype. In contrast, pub18-1/pub19-1 double mutant seeds were less sensitive to ABA and NaCl inhibition of seed germination compared to wild-type seeds, indicating that both PUB-ARM proteins may coordinately function as regulatory components in ABA or salt inhibition of germination.

Assessment of the peripheral hearing system of sport divers.

OBJECTIVE: To investigate the effect of regular scuba diving on the hearing thresholds of sport divers who have no history of noise exposure or ear-related accidents. Comprehensive topographic examination of the peripheral hearing system of sport divers. DESIGN: Cross-sectional study. SETTINGS: General sport diving community. PARTICIPANTS: 81 sport divers with a mean of 300 dives each were compared to a control group of 81 non-divers. MAIN OUTCOME MEASURE: Participants were classified into three age groups. Examination included microscopic otoscopy, tympanometry, pure-tone audiometry (PTA) including air and bone conduction, speech audiometry and otoacoustic emissions (OAE). RESULTS: PTA suggested significant differences of the hearing thresholds at several frequencies between sport divers and non-divers in all age groups, although a Bonferroni correction for multiple testing was applied. Interestingly, the results were contradictory. Divers obtained better hearing results in air conduction, whereas non-divers showed better results in bone conduction. Speech audiometry and OAE did not reveal significant differences. CONCLUSION: There are no published studies of the peripheral cochlear system of divers that have used a combination of PTA, speech audiometry and OAE. All studies suggesting hearing impairment in divers were based on PTA and might have been influenced by a lack of accuracy of PTA. Our results suggest that diving does not adversely affect the hearing system of sport divers. A thorough test battery of audiological methods implying PTA, speech audiometry and OAE may contribute to offer more reliable results to answer the question of whether commercial or military divers are at higher risk for hearing detoriation.

Assessment of the central hearing system of sport divers.

OBJECTIVE: To investigate the effect of regular scuba diving on central processing sequences of sport divers who have no history of noise exposure or ear-related accidents using a comprehensive topographic examination of the central hearing system. DESIGN: Cross-sectional controlled comparison study. SETTINGS: General sports diving community. PARTICIPANTS: 81 sport divers with a mean of 300 dives each were compared with a control group of 81 non-divers. MAIN OUTCOME MEASURE: The participants were classified into three age groups. Hearing test results were combined for both ears. Examination included brainstem evoked response audiometry (BERA), cortical evoked response audiometry (CERA) and dichotic listening tests to screen for retrocochlear and central hearing disorders. Testing of brainstem latencies was performed in a gender-dependent manner. RESULTS: BERA showed a pathological extension of the I-V-latency in one diver. Magnetic tomographic imaging ruled out brainstem lesions. No reason for the measured latency could be detected. All other latencies (I-III, III-V and I-V) in both gender groups were within normal limits. No statistically significant differences between divers and non-divers could be detected. Dichotic listening showed no clinical abnormalities in any of the participants, but in the age group 18-29 years divers performed significantly better than non-divers (p = 0.01). CERA revealed no significant differences between divers and non-divers in the age group 18-29 years and 30-39 years, whereas divers in the age group 41-50 demonstrated significantly better test results (p = 0.045) (difference of the means: 4.18 dB). CONCLUSION: Dichotic listening and CERA did not reveal a significant reduction of central hearing performance in divers. Persistent on-shore BERA wave latency prolongations that were present in one study could not be confirmed in our study group. This first comprehensive topographic examination of the central hearing system of divers showed no abnormalities.

Expression of the AtSUC1 gene in the female gametophyte, and ecotype-specific expression differences in male reproductive organs.

Based on analyses in Arabidopsis thaliana ecotype C24, the AtSUC1 protein was previously characterised as a male gametophyte-specific H(+)/sucrose symporter. Later, expression analyses in ecotype Columbia-0 (Col-0) identified AtSUC1 expression also in trichomes (not detected in trichome-less C24 plants) and roots, suggesting ecotype-specific differences in AtSUC1 expression. Here, we present data on additional ecotype-specific differences in AtSUC1 expression in other tissues. Using different AtSUC1 promoter-reporter gene lines, we performed comparative analyses of AtSUC1 expression in floral tissues of C24 and Col-0 plants, and using an AtSUC1-specific antiserum, we performed immunohistochemical analyses on tissue sections from C24, Col-0, Landsberg erecta (Ler) and Wassilewskaija (Ws) ecotypes. We show that AtSUC1 expression occurs in the funicular epidermis of C24, Ler and Ws, but not in Col-0. In contrast, we observed high levels of AtSUC1 protein in pollen grains of Col-0, lower levels in pollen of C24 and Ler, and no AtSUC1 protein in Ws pollen. Moreover, our reporter gene analyses identified a previously undetected expression of AtSUC1 in the female gametophyte, and revealed that AtSUC1 expression in the funicular epidermis is absent from unpollinated siliques and is induced upon successful pollination. The impact of these findings on the potential physiological role of AtSUC1 is discussed.

[Audiologic rehabilitation of patients with cochlear implants]. / Audiologische Rehabilitation von Kochleaimplantat-Trägern.

The outcome and success of rehabilitation of patients with cochlear implants (CIs) is determined to a large extent by the preoperative diagnostics and individual fitting of the speech processor and is assessed by the auditory performance of the CI recipient. Due to the wide spectrum of auditory abilities of recipients and to the large variability with respect to their age and experience, the postoperative audiologic assessment is based on a large battery of subjective tests and objective measures. The results of these functional tests are used for documenting the level of rehabilitation, and they determine the actions taken for fine-tuning the fitting of the speech processor.

[Universal newborn hearing screening. Methodical aspects]. / Universelles Neugeborenen-Hörscreening. Aspekte des methodischen Vorgehens.

BACKGROUND: In order to prepare for the introduction of a universal newborn hearing screening program on a larger scale, TEOAE and ABR were recorded on automated screening instruments from both ears of 501 newborns at the University Hospital Heidelberg over a period of 13 months. The parents of children in whom OAE and ABR could not be detected in both ears, were requested to allow a complete exploration of the auditory status of the children at the department of pediatric audiology. SUBJECTS AND METHODS: Internally available data networks were used for the acquisition and evaluation of data and for the organization of tracking and follow-up. Of the children 35% exhibited risk factors for congenital hearing impairment. RESULTS: The pass rate was 98.7% for the exclusion of binaural and 91.6% for monaural hearing disorders (TEOAE or ABR detectable). On the basis of the data it can be shown how pass rates can be optimized by selecting a suitable moment for the examination and by prescribing a minimum number of test repetitions (3 for TEOAE and 2 for AABR). CONCLUSION: Quality control of screening programs should include these parameters and, in particular the number of repetitions of test measurements in all screening steps.

[Steady-state responses of the auditory system: a comparison of different methods]. / Stationäre evozierte Potenziale des auditorischen Systems: Ein Methodenvergleich.

BACKGROUND: Determining the hearing threshold in children is one of the most important topics in audiology. Because the existing methods-brainstem evoked response audiometry (BERA) and cortical evoked response audiometry (CERA)-show some severe insufficiencies, it is necessary to look for improved methods. A promising approach may be amplitude modulation following responses (AMFR). In contrast to the conventional transient auditory evoked potentials, these responses show a high-frequency specificity, and they possibly allow statements about the hearing threshold in the low-frequency range. SUBJECTS AND METHODS: The purpose of our study was to objectively detect the hearing threshold in normal-hearing persons of various ages. Pure-tone audiometry served as a subjective control test. For objective tests, we used the measurement of AMFR (two different systems with distinct parameters) and CERA. We compared the different methods with regard to accuracy of the determination of the hearing threshold and investigated the practicability. RESULTS: The results showed some large deviations between the subjective hearing threshold and the objectively determined responses. The lowest deviations appeared at low frequencies. With respect to the variability of results, CERA was clearly superior to AMFR. CONCLUSION: Despite large deviations in the responses objectively determined by AMFR, we think AMFR is suitable to close some gaps in determining objective hearing thresholds, at least at low frequencies.

A mutation in the AtPRP4 splicing factor gene suppresses seed development in Arabidopsis.

The spliceosome catalyzes alternative splicing of many genes in eucaryotic cells. This leads to the expression of distinct proteins. Components of the spliceosome are conserved in mammals and plants. Because splicing can be affected by environmental stress, we analyzed the regulation of splicing-related genes that encode small nuclear ribonucleoprotein particle (snRNP) proteins by the stress hormone abscisic acid (ABA). The transcript abundance of about 25 % of those genes was changed by at least 1.5-fold after addition of ABA. The U4/U6-specific snRNP gene AtPRP4 was strongly repressed by ABA. The homozygous knock-out of AtPRP4 resulted in the suppression of seed development suggesting that the gene product of this stress hormone-regulated gene is crucial for normal seed development.

[On the relation between binaural difference potentials and directional hearing]. / Zur Beziehung zwischen den binauralen Differenzpotentialen und dem Richtungshörvermögen.

BACKGROUND: Central auditory processing disorders (CAPD) are associated with reduced discriminatory abilities of the auditory system. One of these abilities is directional hearing, which is based on the evaluation of interaural signal differences. Since these differences affect also the binaural difference potentials (BDP), these derived evoked potentials could be suitable for the objective detection of disabilities in acoustic localization. METHOD: Auditory brainstem responses (ABR) evoked by monaural and binaural stimulation were recorded in 32 adult normal-hearing volunteers at stimulus levels between 10 and 80 dB nHL and the BDP were derived. Additionally, a test of directional hearing was performed and evaluated. RESULTS: BDP are detectable at all stimulus levels without difficulties, with acceptable examination times and with satisfactory reliability in a routine clinical environment. The electrodes can be positioned at the mastoid (A1 and A2) and vertex (Cz) as for conventional ABR recording. Normal ranges are given for latency and amplitude as well as for their lateral differences. CONCLUSION: The spectrum in directional hearing ability as covered by normal-hearing subjects is not mirrored in the parameters of their BDP. Nevertheless, it cannot be ruled out that a real impairment of directional hearing goes along with significantly altered BDP.