At the Hearing Centre Oldenburg we incorporate our experience from daily work in the evaluation of audio systems and hearing aids into the development of new methods of applied hearing research. Our multidisciplinary team works quantitatively and qualitatively in the fields of audiology, cognition, social research, evaluation technology, usability. Some examples of our method development can be found here:
A new scaling method for laboratory measurements and a new questionnaire for evaluating listening effort in everyday situations were developed in the Hörzentrum Oldenburg.
The adaptive scaling method is an automatic and easy-to-use measurement tool for measuring listening effortin laboratory situations. The measuring time is comparable to that of the well-known speech tests (e.g. Oldenburg sentence test). With the new categorical scaling method, individual level ranges are taken into account by adaptive level calculations. During the measurement, the speech level is changed adaptively and based on the previous assessment of the listening effort, allowing an individual SNR range to be determined for each subject. The task of the test subjects is to evaluate how effortful it was to follow the speaker. For laboratory measurements, the speech material as well as the background noise can be freely selected and adapted to any test situation. Adaptive scaling of listening effort is particularly sensitive in the test area where speech intelligibility measurements can no longer detect differences, i.e. in the area where everything can be understood but it is strenuous to understand everything. This mostly positive SNR range is interesting, for example, for evaluating various hearing system algorithms for noise reduction, since these algorithms can usually only become effective with a positive SNR.
A listening effort questionnaire has been developed for the evaluation of everyday situations. The questions were designed to be answered quickly and easily and to cover situations in quiet, noisy and other demanding conditions (e.g. reverberation, poor acoustics).The hearing situations to be assessed are described in detail. This makes it easier to answer the questions precisely. The results of the listening effort questionnaire and the adaptive scaling method can be combined to provide a complete picture of the individual problem of listening effort.
Dr. Michael Schulte
Cognitive Procedures / Reading Span Test
Many studies have shown that hearing comprehension, especially in noise, depends on cognitive functions such as working memory, word fluency, attention and distractibility. These factors can explain up to 30% of the variance in listening comprehension. There are also findings that the training of cognitive and auditory functions can improve listening comprehension.
The Hörzentrum Oldenburg GmbH develops in cooperation with the University of Oldenburg cognitive methods in the field of hearing care and hearing comprehension in background noise. This is how the Reading Span Test by Carroll et al,2015 came about, which is routinely used alongside the DemTect as a cognitive procedure to evaluate the correlation between the hearing success of hearing aids and cognitive performance. This work takes place in close cooperation with the Excellence Cluster Hearing4all and Task group 3 www.hearing4all.eu/DE/Forschung/A/Task-Group-3.php
Dr. Markus Meis
Bereichsleiter M&W / Divisional Director
Dr. Michael Schulte
Virtual hearing aid
With the "virtual hearing aid", test persons can make sound comparisons by switching directly between different hearing aids without having to put them on and off. This is achieved through signal recordings and play backs in the individual ear canal. During signal playback, the impulse response of the recording and playback apparatus is deducted. With this technology, strengths and weaknesses of the latest generation of commercial hearing aids can be uncovered under the magnifying glass in order to optimize performance and hearing comfort for the hearing impaired prior to their market launch. It can also be used to implement double-blind studies, which are standard practice in the testing of drugs, in hearing systems. The virtual hearing aid allows neither the examiner nor the subject to know which hearing system is currently being evaluated.
Dr. Matthias Vormann
The Hörzentrum developed a questionnaire battery for the German-speaking area to evaluate the outcome of hearing system care, which is distributed via HörTech as "HörTech Questionnaire Inventory(C)". Topics are anamnesis, equipment & service, spontaneous acceptance, listening situations: General & Individual (revision of the "Oldenburger Inventory" by Holube & Kollmeier, 1994), hearing system assessment and quality of life.
Together with Jürgen Kießling (University Hospital Giessen and Marburg) and Hartmut Meister (Jean Uhrmacher Institute), a number of internationally used outcome inventories were translated into German and validated for multi-centre/multilingual studies. These were the three instruments "The Speech, Spatial and Qualities of Hearing Scale" (SSQ), "Satisfaction with amplification in daily life" (SADL) and "Expected consequences of hearing aid ownership" (ECHO). In addition, a German version of the "Hearing-Dependent Daily Activities Scale" (HDDA) for questionnaire-based screening of hearing loss and a questionnaire inventory for sound typing of patients in the field of algorithm and hearing system care were developed and validated.
The questionnaire procedures are used in the context of multi-centre, international studies.
Dr. Markus Meis
Bereichsleiter M&W / Divisional Director
Video-based analysis of interpersonal communication (VIB-AICRAS)
We develop new outcome methods for the evaluation of hearing aids. In addition to classical laboratory tests, everyday tests and questionnaire procedures, we are interested in the extent to which hearing aid algorithms change people's behavior. We use behavioral observations to determine whether the hearing impaired user changes his or her behavior depending on the use of the hearing aid, e.g. whether he or she communicates more frequently and intensively. An established tool is systematic video analysis for the structured interpretation and classification of data. Whether and how the interaction partners relate to each other through physical attention, non-verbal gestures, eye contacts, facial expressions, proxemics and kinesics can be shown in many ways, especially by video recordings: Recorded video can easily be played back more often, it can be viewed by different people and there is time to concentrate on different aspects in detail. For the evaluation we use special software to encode video material according to the Grounded Theory methodology (Glaser/Strauss 1967). The recorded data is structured by codes, which makes the analysis comprehensible for third parties and allows statements and actions to be recorded in a comparative and contrasting manner.
Goals and advantages of video analysis
- New outcome tool in audiology, focused on communication and interaction behavior
- Qualitative and quantitative assessment of the benefits of hearing aid algorithms; hearing aid benchmark
- Evaluation of hearing aids in everyday and realistic situations with several people
- Additional data source to the self-report (questionnaire): the behaviour of several people is evaluated by external observers in order to obtain a more comprehensive picture of the hearing impaired person.
- Statistically evaluable code lists (e.g. behavioral units) as an additional outcome tool in audiology