[Objective frequency-specific measurement of hearing threshold using narrow-band chirp stimuli with level-adaptive simultaneous masking]. / Objektive frequenzspezifische Hörschwellenbestimmung mittels schmalbandiger Chirp-Reize mit pegeladaptiver simultaner Maskierung.

BACKGROUND: In the past, various simulation and measurement paradigms have been introduced and evaluated in order to improve frequency-specific measurement of the hearing threshold using early auditory evoked potentials (EAEP). A promising approach for improvement of detection of stimulus response is the usage of frequency-modulated chirp signals, which optimize the temporal synchrony of neuronal responses along a region of the basilar membrane. AIM OF THE STUDY: This study validated the performance of three generated narrow-band chirp stimuli in combination with a level-adaptive simultaneous masker on a collective of normally hearing subjects. MATERIAL AND METHODS: In this study 25 normal hearing subjects took part after undergoing pure tone audiometry as well as an objective estimation of the auditory threshold using low, middle and high chirp stimuli. The characteristic EAEP parameters were visually identified before statistical analysis. The characteristic latency level function was conducted using measurements within a stimulus level range from 80 to 0 dB HL. Afterwards a comparison of objectively verified auditory threshold and subjective auditory threshold was conducted. RESULTS: All objectively determined thresholds of the frequency-specific evoked EAEP were on average below 10 dB HL: low chirp at 8.2 dB HL, middle chirp at 5.8 dB HL and high chirp at 5.4 dB HL. The mean difference compared to subjectively determined auditory thresholds at all frequencies was below 3 dB and was not significant. CONCLUSION: Brainstem evoked response audiometry (BERA) using a band-limited and level-specific masked chirp stimulus is an efficient method for the determination of frequency-specific excitation thresholds in the clinical routine. The small, insignificant difference compared to the subjectively determined auditory thresholds makes usage of correction factors mostly redundant. Confirming the study results concerning low chirp stimuli so far, the low chirp BERA currently seems to be the method of choice for estimation of auditory threshold at low frequency ranges around 500 Hz.

[Examination of signals for tinnitus sound therapy. Effects of signal dynamics on sound acceptance and tinnitus masking]. / Untersuchungen von Rauschsignalen für die akustische Tinnitustherapie. Auswirkung von Dynamik auf Akzeptanz und Verdeckungswirkung.

BACKGROUND: In terms of sound acceptance and tinnitus-masking efficacy, tinnitus sound therapy appears to be more effective using dynamic natural sounds than static noise signals. The aim of this study was to systematically determine the effects of physical dynamics parameters on tinnitus masking and sound acceptance. MATERIALS AND METHODS: Based on a dynamic model, noise signals with different dynamic properties were synthesized and used to investigate minimal masking levels (MMLs) and spontaneous sound acceptance in six tinnitus patients. RESULTS: High signal dynamics resulted in high MMLs and low sound acceptance. In some instances, low signal dynamics gave rise to slightly lower MMLs than white noise. Despite unfavourable MMLs, natural dynamic sounds were better accepted than synthesized sounds with comparable dynamics. CONCLUSIONS: The higher spontaneous acceptance of natural sounds as compared to white noise appears not to be due solely to physical sound properties, but rather to result primarily from psychological factors. It may be possible to improve sound acceptance in tinnitus sound therapy by using signals with low amounts of dynamics and implementing the use of natural sounds.

Cognitive resources related to speech recognition with a competing talker in young and older listeners.

Speech recognition in a multi-talker situation poses high demands on attentional and other central resources. This study examines the relationship between age, cognition and speech recognition in tasks that require selective or divided attention in a multi-talker setting. Two groups of normal-hearing adults (one younger and one older group) were asked to repeat utterances from either one or two concurrent speakers. Cognitive abilities were then inspected by neuropsychological tests. Speech recognition scores approached its ceiling and did not significantly differ between age groups for tasks that demanded selective attention. However, when divided attention was required, performance in older listeners was reduced as compared to the younger group. When selective attention was required, speech recognition was strongly related to working memory skills, as determined by a regression model. In comparison, speech recognition for tests requiring divided attention could be more strongly determined by neuropsychological probes of fluid intelligence. The findings of this study indicate that - apart from hearing impairment - cognitive aspects account for the typical difficulties of older listeners in a multi-speaker setting. Our results are discussed in the context of evidence showing that frontal lobe functions in terms of working memory and fluid intelligence generally decline with age.

[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.

[Auditory synaptopathy/neuropathy: clinical findings and diagnosis]. / Auditorische Synaptopathie/Neuropathie: Klinik und Diagnostik.

Auditory synaptopathy/neuropathy (AS/AN) is a special subtype of sensorineural hearing disorders with heterogeneous phenotypes and underestimated incidence. AS/AN generally develops in infancy, occasionally in adulthood. Symptoms include fluctuating, mostly bilateral hearing loss and abnormally reduced speech comprehension, especially in noisy environments. Within audiological assessments, patients with AS/AN present otoacoustic emissions (TEOAE; DPOAE) and cochlear microphonics (CM), absence of stapedius reflexes (SR) as well as absent or pathologically altered auditory evoked brainstem potentials (ABR). Children with AS/AN cannot be identified within OAE-based newborn hearing screening programs. Clinical findings, transtympanic electrocochleography (ECoG) and further diagnostic tools permit further identification of individual characteristics. In individual cases conventional amplification and the use of FM systems may improve hearing and communication skills. If these interventions, accompanied by intensive hearing, speech and language therapy are unsuccessful, cochlear implants (CI) or alternative forms of communication may be useful options for rehabilitation.

[Examination of speech perception and cognitive functioning in the elderly]. / Untersuchungen zum Sprachverstehen und zu kognitiven Fähigkeiten im Alter.

BACKGROUND: Elderly persons frequently complain about problems with speech understanding especially in complex acoustic situations. Besides hearing impairment the decline of cognitive functions might explain these problems. METHODS: In 12 normal hearing young subjects and 14 elderly listeners with extraordinarily good hearing speech perception was measured in a broad range of different acoustic situations. Cognitive functioning was evaluated with different neuropsychological tests. RESULTS: Despite comparable pure tone thresholds the elderly listeners revealed worse speech discrimination than the young subjects in almost all test situations. Largest differences were found in situations with fluctuating maskers and competing talkers. Most of the speech perception results revealed significant correlations with the outcome from a neuropsychological test addressing declarative verbal memory. CONCLUSIONS: In complex listening situations elderly persons reveal worse speech understanding than younger subjects. Differences in speech perception can partly be attributed to cognitive abilities. In particular, working memory seems to be an important factor.

[Development of a German version of the Functioning After Pediatric Cochlear Implantation (FAPCI) questionnaire]. / Entwicklung einer deutschsprachigen Version des Fragebogens Functioning After Pediatric Cochlear Implantation (FAPCI).

BACKGROUND: The Functioning After Pediatric Cochlear Implantation (FAPCI) instrument was recently developed to determine the communicative performance of 2-5-year-old prelingually deafened, cochlear-implanted children. Because of its high reliability and validity, as well as possible additional information compared with existing questionnaires, the 23-item parent-proxy questionnaire was translated from U.S. English to German prior to validation. MATERIAL AND METHODS: Initially, the German inventory was qualitatively developed by experts in audiology and speech pathology in collaboration with a professional American translator. Based on a sample of parents' responses, the outcome was quantitatively validated using psychometric methods (Cronbach's alpha, principal components analysis). Finally, the nomological validity was verified by correlating the overall FAPCI value with an external criterion (i.e., hearing age). RESULTS: For almost all age groups, Cronbach's alpha exceeded the minimum value of the original study (0.86). Principal components analysis revealed a two-factor solution (speech perception/production). The fitting of a nonparametric regression line to the data points showed that the total FAPCI score was positively associated with the time of implant use. CONCLUSION: The results show concordance between the German and the English versions of the FAPCI. The two instruments agree in reliability as well as in validity. The suitability of the German version in the clinical and therapeutic routine needs to be confirmed in further investigations.

[Examining informational masking in cochlear implant users]. / Untersuchungen zum "Informational Masking" bei Kochleaimplantat-Nutzern.

BACKGROUND: Informational masking (IM) refers to the problem of understanding target speech in the simultaneous presence of a masking speech signal. The adverse effects are attributable to the additional information provided by the competing talker. Cochlear implant (CI) recipients are not able to understand speech satisfactorily in situations such as these. The aim of the present study is to examine the extent to which CI recipients are able to use differences between the speakers with respect to level (target-to-masker ratio, TMR) and fundamental frequency (f0) in order to improve speech intelligibility. SUBJECTS AND METHODS: Target (TS) and masker sentences (MS) were selected from the Oldenburg Sentence Test (OlSa) and were modified and superimposed. The TS were explicitly labelled using a keyword. The MS were changed with respect to TMR and f0. The TS intelligibility of different modifications was measured in six post-lingually deafened CI recipients and six normal listeners (NL). RESULTS: The NL revealed speech understanding close to 100% even for small differences in f0 of 40 Hz or level differences of 5 dB. In CI recipients, a significant change in intelligibility could only be demonstrated with increased TMR, but not with differences in f0. CONCLUSIONS: In CI recipients, IM cannot be reduced by means of differences in f0 between the competing talkers, but only by level differences. This might be explained by the restricted spectral resolution and the insufficient transmission of f0 in CIs. Adverse effects in NL can predominantly be attributed to IM, while additional masking effects take place in CI recipients.

[Conception and realisation of a prosody test battery]. / Konzeption und Realisierung einer Prosodie-Testbatterie.

BACKGROUND: Prosody reflects rhythmic and melodic aspects in speech and is one of the quality measures that shows--apart from pure speech understanding--a rising interest in the assessment of technical hearing aids, especially of cochlear implants. At present, there is no adequate test battery for the German speaking population. The test battery presented in this study aims to fill this gap. METHODS: The test battery consists of four different modules addressing different prosodic cues, namely duration, question vs statement, sentence stress, and speaker gender. One part of the test battery aims at reflecting everyday situations and was realized with six different speakers representing various pitch frequencies and speak rates. Another goal of the tests is to detect very small differences in prosody perception. Therefore, natural utterances were artificially modified by changing the underlying acoustic parameters (e.g. duration, fundamental frequency). Measurements were performed with 12 normal listeners in order to investigate the properties of the tests. RESULTS: As expected, the normal listeners revealed discrimination rates of close to 100% in that part of the test battery using natural utterances. For the part with the modified stimuli, all four modules revealed very steep discrimination functions indicating that the normal listeners were able to use very small changes in the acoustic parameters as cues for prosody perception. Moreover, the slope of the discrimination function revealed very low variability. CONCLUSIONS: Together with preliminary data from cochlear implant recipients who clearly showed different psychometric functions, the test battery seems suitable for a comprehensive evaluation of prosody perception. This facilitates future examinations of speech processing beyond the pure understanding of speech.

[Experiments on prosody perception with cochlear implants]. / Experimente zur Perzeption prosodischer Merkmale mit Kochleaimplantaten.

BACKGROUND AND OBJECTIVE: Prosody has a myriad of linguistic functions and involves specific aspects of speech, such as stress, intonation and pauses. The underlying acoustic quantities (amplitude envelope, pitch frequency, and temporal structure) can be processed and transmitted by cochlear implants (CI) only to a limited extent. At present, no adequate tests are available in the German-speaking world for evaluation of the perception of prosodic elements. Different experiments have been conducted to address several prosodic cues, and the results are to be used as a basis for appropriate tests. METHODS: Various prosodic materials were used for the experiments. Discrimination was measured for minimal pairs differing in frequency and/or duration, accents in words and phrases, questions versus statements and phrasing. Measurements were performed in ten normal-hearing subjects and five with cochlear implants. RESULTS AND CONCLUSIONS: In all test modules, the subjects with normal hearing proved to have high discrimination rates of 96-100%. The test of word stresses was problematic because the results were influenced by different confounders. The other measurements did prove to be basically suitable for use in the subjects with implants. Early results revealed that the subjects with CI had few problems with prosodic cues based on the temporal structure, the outcome being similar to that of the subjects with normal hearing in these tests. In contrast, the performance of subjects with CI in perceiving prosodic cues based on amplitude variations and, especially, on alterations in pitch frequency was worse, even though some of them achieved very good results in these tests too. These preliminary tests can form the basis for development of a German-language prosody test battery with a limited number of subtests addressing different prosodic cues.

[Diagnosis and therapy of auditory synaptopathy/neuropathy]. / Diagnostik und Therapie der auditorischen Synaptopathie/Neuropathie.

Pathological auditory brainstem responses (lack of responses, elevated thresholds and perturbed waveforms) in combination with present otoacoustic emissions are typical audiometric findings in patients with a hearing impairment that particularly affects speech comprehension or complete deafness. This heterogenous group of disorders first described as "auditory neuropathy" includes dysfunction of peripheral synaptic coding of sound by inner hair cells (synaptopathy) and/or of the generation and propagation of action potentials in the auditory nerve (neuropathy). This joint statement provides prevailing background information as well as recommendations on diagnosis and treatment. The statement focuses on the handling in the german language area but also refers to current international statements.

[A measurement system for assessing binaural masking level difference (BMLD) in children]. / Messsystem zur Erfassung der "binaural masking level difference" (BMLD) bei Kindern.

BACKGROUND: The binaural masking level difference (BMLD) is defined as the contrast between homophasic and antiphasic signal conditions, and can be regarded as a measure for noise suppression by the auditory system. METHODS: An adaptive two interval forced choice (IFC) measurement method was designed to assess BMLDs in children. The target tone was a 500 Hz sine pip which was masked with narrow band noise. The presentation of homo- and antiphasic signals was staggered in order to take into account artefacts--such as changes in vigilance--in a similar manner for both conditions. RESULTS: Measurement was feasible in 57 out of 85 children (6-14 y.) with suspected auditory processing disorders. Mean BMLD was 7.4(+/-4.5 SD) dB. Five children revealed a BMLD close to 0 dB suggesting that they had no advantage in signal detection for the antiphasic condition. Eleven children were not able to cope with the task of measurement. In another 17 children, the measurements did not converge to a stable threshold. DISCUSSION: The proposed measurement method was feasible with most of the children. With slight modifications of the threshold convergence, this proportion can be further increased. Whether or not the large inter-individual scatter of the results is an expression of the heterogeneous clinical clientele can only be determined when normative data are available.

A new approach to pharmacological effects on ciliary beat frequency in cell cultures--exemplary measurements under Pelargonium sidoides extract (EPs 7630).

The ciliary beat frequency (CBF) is an important parameter of the defence mechanism of the mucociliary system. We present a new method to determine pharmacological effects on CBF in vitro. Ciliated cell cultures of human nasal epithelium were obtained from partial resection of hyperplastic inferior turbinates in rhinosurgery. An adherent monolayer culture of ciliated cells was present after 10 days in vitro. This study exemplary examines, if a special extract from the roots of Pelargonium sidoides (EPs 7630) has an effect on the CBF in vitro. The influence of three concentrations of the extract (1, 30, 100 microg/ml) was tested. EPs 7630 significantly and concentration-dependently increased CBF to 123% at 30 microg/ml and to 133% at 100 microg/ml compared to the equilibration phase (100%). After rinsing with extract-free medium the CBF of cultured cells returned to nearly the normal range. In future, drug manipulation of the CBF by local application of rhinologics could be a new therapeutical concept in the treatment of upper airway diseases.

[Identifying factors before the provision of hearing aids. Results from a pilot study]. / Untersuchung von Faktoren bei der Erstversorgung mit Hörgeräten. Ergebnisse einer Pilotstudie.

OBJECTIVE: Systematic research on factors before the provision of hearing aids is scarce. In order to identify parameters which promote or impede the use of hearing aids, a questionnaire-based survey was conducted. SUBJECTS AND METHODS: A total of 35 randomly chosen, hard of hearing adults indicated for a hearing aid were examined. The importance of speech in quiet and in noise, wearing comfort, sound quality, appearance and costs, as well as expectations, willingness to use a hearing aid and reasons for and against provision were determined. RESULTS: Speech in noise and quiet were most important, followed by comfort of wearing and appearance of the aid. Expectations towards the hearing aids were in general high. The willingness to use hearing devices was positively affected by the expectation that it would improve quality of life and negatively by the amount of social activity of the person. The main reasons against the use of hearing aids were appearance and lack of confidence in hearing aid technology. CONCLUSIONS: This pilot-study identified several parameters which might affect willingness to use hearing aids. In particular, expectations towards the aids, personal attitude towards hearing and communication problems and the appearance of hearing aids should be subject to further examination.