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1.
HNO ; 61(1): 38-45, 2013 Jan.
Article in German | MEDLINE | ID: mdl-23272323

ABSTRACT

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.


Subject(s)
Acoustic Stimulation/instrumentation , Acoustic Stimulation/methods , Patient Acceptance of Health Care/psychology , Sound Spectrography , Tinnitus/psychology , Tinnitus/therapy , Adult , Female , Humans , Male , Middle Aged , Patient Satisfaction , Perceptual Masking
2.
HNO ; 59(7): 689-95, 2011 Jul.
Article in German | MEDLINE | ID: mdl-21509624

ABSTRACT

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.


Subject(s)
Cognition Disorders/diagnosis , Cognition Disorders/physiopathology , Cognition , Hearing Disorders/diagnosis , Hearing Disorders/physiopathology , Speech Perception , Adolescent , Adult , Aged , Cognition Disorders/complications , Female , Hearing Disorders/complications , Humans , Male , Middle Aged , Young Adult
3.
HNO ; 57(7): 678-84, 2009 Jul.
Article in German | MEDLINE | ID: mdl-19517081

ABSTRACT

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.


Subject(s)
Cochlear Implants , Deafness/diagnosis , Deafness/rehabilitation , Hearing Tests/methods , Recovery of Function , Surveys and Questionnaires , Child, Preschool , Humans , Male , Reproducibility of Results , Sensitivity and Specificity , Treatment Outcome
4.
HNO ; 57(7): 671-7, 2009 Jul.
Article in German | MEDLINE | ID: mdl-19517083

ABSTRACT

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.


Subject(s)
Cochlear Implants , Deafness/diagnosis , Deafness/rehabilitation , Hearing Tests/methods , Perceptual Masking , Adult , Female , Humans , Male , Middle Aged , Treatment Outcome
5.
HNO ; 56(3): 340-8, 2008 Mar.
Article in German | MEDLINE | ID: mdl-17579822

ABSTRACT

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.


Subject(s)
Cochlear Implants , Deafness/diagnosis , Deafness/rehabilitation , Outcome Assessment, Health Care/methods , Speech Discrimination Tests/methods , Speech Disorders/diagnosis , Speech Disorders/rehabilitation , Acoustic Stimulation/methods , Adult , Deafness/complications , Female , Humans , Male , Reproducibility of Results , Sensitivity and Specificity , Speech Disorders/etiology , Treatment Outcome
6.
HNO ; 55(4): 264-70, 2007 Apr.
Article in German | MEDLINE | ID: mdl-17004071

ABSTRACT

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.


Subject(s)
Acoustic Stimulation/methods , Cochlear Implants , Hearing Loss/diagnosis , Hearing Loss/therapy , Pitch Perception , Speech Discrimination Tests/methods , Speech Perception , Adult , Female , Humans , Male , Music , Reproducibility of Results , Sensitivity and Specificity , Treatment Outcome
7.
HNO ; 54(11): 833-9, 2006 Nov.
Article in German | MEDLINE | ID: mdl-17041780

ABSTRACT

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.


Subject(s)
Cochlear Nerve , Hearing Loss, Sensorineural/diagnosis , Synapses , Vestibulocochlear Nerve Diseases/diagnosis , Brain Stem/physiopathology , Child , Child, Preschool , Cochlear Implantation , Cochlear Nerve/physiopathology , Deafness/diagnosis , Deafness/physiopathology , Evoked Potentials, Auditory, Brain Stem/physiology , Hair Cells, Auditory, Inner/physiopathology , Hearing Aids , Hearing Loss, Sensorineural/physiopathology , Hearing Loss, Sensorineural/rehabilitation , Humans , Infant , Infant, Newborn , Otoacoustic Emissions, Spontaneous/physiology , Speech Perception/physiology , Speech Reception Threshold Test , Spiral Ganglion/physiopathology , Vestibulocochlear Nerve Diseases/physiopathology , Vestibulocochlear Nerve Diseases/rehabilitation
8.
HNO ; 52(9): 790-7, 2004 Sep.
Article in German | MEDLINE | ID: mdl-15372170

ABSTRACT

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.


Subject(s)
Hearing Aids/statistics & numerical data , Hearing Loss/epidemiology , Hearing Loss/rehabilitation , Patient Compliance/statistics & numerical data , Patient Satisfaction/statistics & numerical data , Quality of Life , Adult , Aged , Aged, 80 and over , Attitude to Health , Data Collection , Female , Germany/epidemiology , Humans , Male , Middle Aged , Patient Acceptance of Health Care/statistics & numerical data , Pilot Projects
10.
HNO ; 51(2): 125-33, 2003 Feb.
Article in German | MEDLINE | ID: mdl-12589418

ABSTRACT

BACKGROUND AND OBJECTIVE: At present, only a small number of validated, clinically usable methods for the assessment of binaural hearing capabilities exist. A proposed electrophysiological measure is the registration of the brainstem-based binaural difference potentials (BDP). PATIENTS/METHODS: The BDP is calculated as the difference between the binaurally evoked registration and the sum of the two monaural registrations. Detection and stability of the BDP were examined in 24 normally hearing adults within the framework of conventional registration of auditory brainstem responses. Furthermore, the influence of interaural time differences (ITD) on the BDP was determined. In addition, lateralization of the subjects was assessed using a psychoacoustical method. RESULTS: The components of the BDP could be detected in almost all of the subjects. Moreover, they showed sufficient test-retest reliability. The impact of ITD,which causes lateralization of the stimulus,was clearly detectable for the latencies and the amplitudes of the BDP. CONCLUSIONS: Binaural difference potentials, which are easily and reliably detectable reveal a relationship to the outcome of psychoacoustical assessment of lateralization and have the potential to provide a measure for binaural hearing capacity.


Subject(s)
Dichotic Listening Tests , Evoked Potentials, Auditory, Brain Stem/physiology , Functional Laterality/physiology , Acoustic Stimulation , Adolescent , Adult , Auditory Threshold/physiology , Brain Stem/physiology , Female , Humans , Male , Middle Aged , Psychoacoustics , Reaction Time/physiology , Reference Values , Signal Processing, Computer-Assisted , Sound Localization/physiology
11.
HNO ; 49(6): 458-64, 2001 Jun.
Article in German | MEDLINE | ID: mdl-11450513

ABSTRACT

BACKGROUND AND OBJECTIVE: Loudness measurements in children have been carried out using different psychoacoustical methods. Besides absolute magnitude estimation (AME) and cross modality matching (CMM) category and non-category loudness scalings have been performed. However, there is a lack of systematic evaluation in loudness scalings with children. PATIENTS/METHODS: A clinically feasible categorical method is presented which was evaluated in 10 normally hearing children of 7 to 8 years. Furthermore, measurements with hearing disabled children were performed in the framework of hearing aid evaluation. RESULTS: Normal hearing children scaled slightly louder than a group of adult subjects with normal hearing. Regarding the shape of the loudness functions measured they were very similar. Particularly, they showed a steeper course at higher levels than for low input signals. Intraindividual scatter of the loudness judgements was larger for children than for adults. However, high correlation appeared between the data across test and retest. Hence, the outcome of the scalings appears to be sufficient reliable. CONCLUSIONS: Clinical measurements confirmed that the method is appropriate for children from approximately 5-10 years. Loudness judgements became more consistent and more subtly differentiated with increasing age and decreasing hearing loss. Especially with view of hearing aid evaluation the method can give valuable indications because of the possibility to directly measure individual loudness over a broad range of levels and frequencies.


Subject(s)
Loudness Perception , Adult , Child , Child, Preschool , Female , Hearing Aids , Humans , Male , Pitch Perception , Psychoacoustics , Reference Values , Reproducibility of Results
12.
Ear Hear ; 22(2): 142-50, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11324843

ABSTRACT

OBJECTIVE: To introduce conjoint analysis (CA) as a method to explain choice decisions of hearing aid users and to measure the contributions of different hearing aid attributes involved. DESIGN: The study was conducted using CA, a method that is well established in marketing, but has not been used for hearing aid research. CA examines the contributions (importance) various attributes make to overall preference judgements. It is based on the premises that objects (i.e., hearing aids) can be described as different combinations of several attributes. The relative importance of the attributes is estimated from integral judgements of hypothetical hearing aids. The advantages of CA are a more realistic presentation of complete products instead of isolated attributes and the consideration of trade-offs between the features. The following attributes selected from 12 features in a prestudy were included in the application: speech perception in quiet, speech perception in noise, handling, sound quality, localization, and feedback. 93 randomly chosen experienced hearing aid wearers participated in the survey. RESULTS: It was found that the attributes concerning speech perception were by far most important. Speech discrimination in quiet and in noise were almost equally significant and contributed with 56% to the preference decisions of the subjects. The remaining attributes showed values in the range of 10% to 12%. When comparing various subgroups dependent on age, sex, hearing loss, satisfaction, etc., significant differences concerning the preferences were found. Elder and female subjects attached greater importance of the attribute "handling" whereas younger patients judged "speech in noise" more important. In general, subjects with greater hearing loss considered speech intelligibility in quiet to be more important than in noisy surroundings. Moreover, sound quality seems to be a significant indicator for satisfaction with the hearing aid. CONCLUSIONS: This study proposes CA as a survey technique to examine individual preferences for hearing aids. Several assumptions about the importance of hearing aid features for different groups of users could be confirmed quantitatively. Segmentation showed valid results depending on socio-demographic and user-specific parameters. The method used and the results are of interest for audiologists as well as the hearing aid industry. They provide valuable tools for future hearing aid design and should be considered in the development of self-assessment inventories.


Subject(s)
Correction of Hearing Impairment , Hearing Aids/standards , Speech Perception/physiology , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Noise , Random Allocation , Surveys and Questionnaires
13.
Int J Pediatr Otorhinolaryngol ; 57(2): 129-36, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11165650

ABSTRACT

OBJECTIVE: The question whether progressive sensorineural hearing loss during childhood is the fateful course of a main illness has been discussed controversially over 60 years. No medicamentous therapy with satisfactory results has been described in the literature. The goal of this study was to determine whether an infusion therapy, developed for the treatment of sudden hearing loss in the elderly, can induce recovery after progression in sensorineural hearing loss during childhood. METHODS: Out of 20 children suffering from acute progression in sensorineural hearing loss, seven children were treated with an infusion therapy containing prednisolone, pentoxifylline and a plasma expander (group I), and 13 children were not treated (group II). All children were advised not to use hearing aids for 6 weeks. RESULTS: In group I, we observed partial to complete restoration of hearing threshold towards the original hearing threshold given by previous routine controls in 6/7 children. In group II, only three children recovered, with the state of ten children's' hearing loss remaining unchanged. The long-term follow-up, however, showed no distinct difference in either group. CONCLUSION: Infusion therapy can be helpful when treating acutely progressing sensorineural hearing loss during childhood. The benefit for communicative competence has to be discussed. Further studies should be conducted.


Subject(s)
Hearing Loss, Sensorineural/drug therapy , Pentoxifylline/therapeutic use , Plasma Substitutes/therapeutic use , Prednisolone/therapeutic use , Case-Control Studies , Child , Child, Preschool , Disease Progression , Drug Therapy, Combination , Follow-Up Studies , Humans , Pentoxifylline/administration & dosage , Plasma Substitutes/administration & dosage , Prednisolone/administration & dosage , Retrospective Studies , Time Factors
15.
HNO ; 48(4): 287-94, 2000 Apr.
Article in German | MEDLINE | ID: mdl-10810675

ABSTRACT

The benefit of innovative hearing aid technology can be evaluated in clinical trials. The present study describes the comparison of a new digital hearing aid with an analogue device serving as a reference. The tests were carried out with 15 experienced hearing aid wearers. To prevent the influence of different fitting algorithms such as prescriptive or loudness-based the digital devices were not renewed fitted but their level- and frequency-depending gain was adjusted to that of the reference. Different tests concerning loudness perception (category loudness scaling) speech discrimination in noise (the Göttingen sentence test) and self-assessment of the benefit by questionnaires were performed. All tests yielded slightly better results for the digital hearing aid. The speech audiometric evaluation showed somewhat better discrimination for the test-device. The questionnaires yielded a marked preference for the digital device. Because the study was not blinded influences due to the knowledge of the subjects of testing a new technology generally can occur. On the other hand, the question arises whether present audiometric tests sufficiently consider signal processing of modern hearing systems. Furthermore, one has to take into account that only a few of the features of digital technology such as noise-reduction and feedback-cancellation were considered in this study to allow for a sensible comparison. Because of the large number of possibilities offered by digital technology additional benefit by the hearing aid can be expected.


Subject(s)
Analog-Digital Conversion , Hearing Aids , Microcomputers , Signal Processing, Computer-Assisted/instrumentation , Audiometry, Speech , Humans , Patient Satisfaction , Prosthesis Fitting , Speech Discrimination Tests
16.
HNO ; 48(3): 189-94, 2000 Mar.
Article in German | MEDLINE | ID: mdl-10768109

ABSTRACT

The loudness perception of patients with hearing aids was measured with a one-stage category loudness scaling procedure. Data were obtained from 102 ears and were studied primarily in older patients who represented the majority of patients with hearing disorders evaluated in our department. In all, 75% of the patients were older than 45 years and had a mean age of 58 years. The reduction of dynamics at high frequencies was considered to be typical for age-related hearing disorders and was easily quantified with loudness scaling. Findings demonstrated that prediction of recruitment was not possible from pure-tone thresholds or even together with uncomfortable loudness levels, since the slopes of the level-loudness functions revealed a high interindividual variability. In contrast, the desired compression ratio can be easily calculated with data from the loudness scaling. In this study the loudness perception of patients with mainly non-linear hearing aids fitted with customary procedures was evaluated. The benefit from the hearing aids was proven with the outcome from the loudness scaling, with testing also allowing for a better fitting of the aids.


Subject(s)
Hearing Aids , Hearing Loss, Sensorineural/rehabilitation , Loudness Perception , Recruitment Detection, Audiologic , Adult , Aged , Diagnosis, Computer-Assisted , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Prosthesis Fitting
17.
HNO ; 48(3): 195-203, 2000 Mar.
Article in German | MEDLINE | ID: mdl-10768110

ABSTRACT

Several investigations prove that monaural acoustic deprivation induces detrimental changes in the auditory pathway. So far the major interest focused on degenerative processes on the deprived side, while effects on the contralateral untreated side were not taken into consideration. This ontogenetic study investigates effects of early monaural acoustic deprivation on the functional development of the acoustically evoked auditory brainstem response (ABR) in the Mongolian gerbil. Young gerbils were deafened by a single intracochlear application of neomycin sulfate. The ABR development on the contralateral side differed in a late developmental period from that of normally hearing animals. These changes persisted until adulthood. Between day 55 and day 90 a significant 5 dB decrease of the ABR thresholds and a significant shortening of the interpeak latency II-V occurred. The results confirm that a complete monaural deprivation during the sensible or critical period leads on the contralateral side to plastic or compensatory changes in the auditory brainstem.


Subject(s)
Auditory Pathways/physiopathology , Auditory Perception/physiology , Evoked Potentials, Auditory, Brain Stem/physiology , Functional Laterality/physiology , Sensory Deprivation/physiology , Age Factors , Animals , Auditory Threshold/physiology , Brain Stem/physiopathology , Female , Gerbillinae , Male , Neuronal Plasticity/physiology
18.
HNO ; 48(3): 204-8, 2000 Mar.
Article in German | MEDLINE | ID: mdl-10768111

ABSTRACT

The sound transmission properties of three different commercially available middle ear implants and the prototype of a complete middle ear prosthesis (CoMEP) were evaluated with a special measurement system that permits standardized conditions. This system uses a mechanical middle ear model (MMM) which approximates the impedances of the tympanic membrane and inner ear. The implants were fitted under defined conditions into the MMM. Displacement of the artificial stapes footplate of the MMM was measured with an optical probe. The measurements of different middle ear prostheses showed that the mass of the implant was the most important factor for optimum high frequency transmission. The lightest implant (4 mg, titanium) showed the best results. The CoMEP revealed the highest sensitivity because of a slight enlargement of the diameter of the artificial tympanic membrane. These findings show that the CoMEP is able to restore sound transmission to a normal range. In a second experiment one of the implants was fitted into the MMM with different forces. The increase of stiffness produced a slightly better high frequency transmission at the expense of low frequency sensitivity. Hence, the fitting of the implant may not be too stiff because of its loss of mobility within a significant frequency range.


Subject(s)
Hearing/physiology , Ossicular Prosthesis , Acoustic Impedance Tests , Humans , Models, Anatomic , Pitch Perception/physiology , Prosthesis Design , Prosthesis Fitting , Tympanic Membrane
19.
HNO ; 48(3): 209-14, 2000 Mar.
Article in German | MEDLINE | ID: mdl-10768112

ABSTRACT

One of the problems when providing prelingually deafened children with a cochlear implant is to find the optimal moment for the implantation in order to make optimal use of the sensitive phase in the maturation of the auditory system and to achieve the maximum improvement of hearing. Ontogenetic questions can be investigated in animal experiments under controlled conditions. In the present study an animal model (gerbil, Meriones unguiculatus) was established to simulate the situation of prelingually deafened children and to examine the influence of chronic electrostimulation on the development of the auditory pathway. We used species specific sounds for chronic stimulation to simulate significance of human language in our animal modell. A daily two-hour electrostimulation during the ontogenesis of early deafened animals lead to a partial compensation of the functional degeneration of the auditory pathway, which can be observed in totally deafened animals. This animal model provides an elaborate test design which can be used in CI research for the investigation of numerous problems.


Subject(s)
Auditory Pathways/physiopathology , Cochlear Implants , Disease Models, Animal , Sensory Deprivation/physiology , Speech Perception/physiology , Animals , Brain Stem/physiopathology , Evoked Potentials, Auditory, Brain Stem/physiology , Gerbillinae , Humans , Infant , Sound Spectrography , Speech Acoustics
20.
Scand Audiol ; 29(1): 3-9, 2000.
Article in English | MEDLINE | ID: mdl-10718671

ABSTRACT

Recent studies have revealed marked differences in the prevalence of hearing impairment in childhood. It remains unknown whether this is caused by geographic, sociocultural or ethnic factors. In order to provide consistent data, 314 children in residence at a school for hearing impaired children of a well-defined German area were investigated retrospectively. We estimated an overall prevalence of .43/1000 of hearing impairment for this area. A striking variability between different nationalities could be observed. For German children, the prevalence was .36/1000, for Turkish 1.04/1000 and for Italian children 1.37/1000. Hereditary hearing losses and, in particular, autosomal recessive caused hearing disorders were the most common cause of hearing impairment in foreign but not in native children. One reason might be the frequency of marriages between relatives resulting from the social isolation of the foreign groups in German society.


Subject(s)
Hearing Disorders/epidemiology , Hearing Disorders/genetics , Adolescent , Adult , Child , Child, Preschool , Female , Germany/epidemiology , Humans , Italy/ethnology , Male , Prevalence , Retrospective Studies , Turkey/ethnology
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