Præsentationer på ISAAR 2017

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Anne Wolff, Raul Sanchez, og Sabina Storbjerg Houmøller, tre PhD studerende i BEAR projektet vil præsentere deres arbejde ved the International Symposium on Auditory and Audiological Research (ISAAR), som finder sted i Nyborg den 23-25 august, 2017. Også to kandidatstuderende i akustik og lydteknologi ved Aalborg Universitet (Sigurd Møller van Hauen og Andreas Harbo Rukjær) giver en præsentation, som er inspireret og støttet at BEAR projektet.

Nedenfor er listet alle BEAR bidragenes abstrakts til symposiet (alle på engelsk):

National Better hEAring Rehabilitation (BEAR) project: A status on the database with special focus on patients’ motivation on hearing aid treatment

Anne Wolff – Department of Otolaryngology, Head & Neck Surgery and Audiology, Aalborg University Hospital, Aalborg, Denmark
Sabina Storbjerg Houmøller – Department of ENT/Audiology, Odense University Hospital, Odense, Denmark
Michael Gaihede, Dan Hougaard – Department of Otolaryngology, Head & Neck Surgery and Audiology, Aalborg University Hospital, Aalborg, Denmark; Department of Clinical Medicine, Aalborg University Hospital, Aalborg, Denmark
Jesper Hvass Schmidt – Department of ENT/Audiology, Odense University Hospital, Odense, Denmark
Dorte Hammershøi – Department of Electronic Systems, Aalborg University, Aalborg, Denmark 

It is estimated that around 250,000 people (DK) own a hearing aid (HA) and that about 20% do not use their hearing aids regularly. The reasons for this are not understood, but it is clear that these 20% do not perceive the benefit of their devices to be sufficient. The goal of the BEAR is to improve hearing rehabilitation through an update of clinical practice. As a part of the BEAR project a clinical database has been created to document the current hearing aid treatment of hearing impaired people in Denmark. The database will collect knowledge of different aspects that may prove to be important for user satisfaction. Data are collected from consecutive clinical data, from the Dept. of Audiology Odense and Aalborg University Hospital, and from several additional questionnaires. As a part of the survey the patients are asked to score their motivation to acquire a HA. With the use of the database it is possible to analyze whether one or more of patient stand out compared to others. A status on demographic data compared with motivational scores will be presented. Whether HA-motivation of the individual patients has an essential role in user satisfaction is not well investigated. With this project a broad variety of variables will be investigated and the aim is to identify clinically relevant subgroups which previous studies have not been able to succeed in.

Data-driven approach for auditory profiling

Raul H. Sanchez, Federica Bianchi, Michal Fereczkowski – Hearing Systems, Department of Electrical Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark
Sébastien Santurette – Hearing Systems, Department of Electrical Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark; Department of Otorhinolaryngology, Head and Neck Surgery & Audiology, Rigshospitalet, Copenhagen, Denmark
Torsten Dau – Hearing Systems, Department of Electrical Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark 

Nowadays, the pure-tone audiogram is the main tool used to characterize hearing loss and to fit hearing aids. However, the perceptual consequences of hearing loss are typically associated not only with a loss of sensitivity, but also clarity loss that is not captured by the audiogram. Detailed characterization of hearing loss has to be simplified to efficiently investigate the specific compensation needs of individual listeners. We hypothesized that any listeners’ hearing can be characterized along two dimensions of distortion: type I and type II. While type I can be linked to factors affecting audibility, type II reflects non-audibility-related distortions. To test our hypothesis, the individual performance data from two previous studies was re-analyzed using archetypal analysis. Unsupervised learning was used to identify extreme patterns in the data which form the basis for different auditory profiles. Next, a decision tree was determined to classify the listeners into one of the profiles. The new analysis provides evidence for the existence of four profiles in the data. The most significant predictors for profile identification were related to temporal processing, loudness growth, and speech perception. The current approach is promising for analyzing other existing data sets in order to select the most relevant tests for auditory profiling.

BEAR: A status on population characteristics of hearing-aid users obtained from the database

Sabina Storbjerg Houmøller – Department of ENT/Audiology, Odense University Hospital, Odense, Denmark
Anne Wolff, Dan Dupont – Department of Otolaryngology, Head & Neck Surgery and Audiology, Aalborg University Hospital, Aalborg, Denmark
Dorte Hammershøi – Department of Electronic Systems, Aalborg University, Aalborg, Denmark
Christian Godballe, Jesper Hvass Schmidt – Department of ENT/Audiology, Odense University Hospital, Odense, Denmark 

Recent studies estimate that around 20% of the hearing aid (HA) owners in Denmark do not regularly use their HA, which implies that they are not satisfied with the HA treatment and did not experience the benefits they expected. The overall vision of the BEAR project is to improve hearing rehabilitation in Denmark through an evidence-based renewal of clinical practice and optimization of the individual HA fitting, resulting in a successful hearing aid treatment. Initially the project aims to describe the current clinical practice, by building a clinical database containing the existing data on HA profiling and fitting strategies. Data from 2000 patients are collected from the departments of Audiology in Odense and Aalborg University Hospital. Some of the registered variables include gender, age, and health related questions, noise exposure and whether they are suffering from tinnitus. The database thereby contains descriptive data on the current population of HA users in Denmark and their health status. Descriptive data in different relevant subgroups of HA users obtained from the database will be presented. Based on the results, analyses of average age and the distribution of gender in different subgroups of HA users, including experienced versus new HA users will be made. Previous noise exposure and the relation to the occurrence of tinnitus will be investigated as well.

Estimating Auditory Filter Bandwidth with Distortion Product Otoacoustic Emissions

Sigurd Møller van Hauen, Andreas Harbo Rukjær – M.Sc. students in Acoustics and Audio Technology, School of Information and Communication Technology, Aalborg University, Aalborg, Denmark
Rodrigo Ordoñez, Dorte Hammershøi – Signal and Information Processing, Department of Electronic Systems, Aalborg University, Aalborg Denmark

The basic frequency selectivity in the listener’s hearing is often characterized by auditory filters. These filters are determined through listening tests, which determine the masking threshold as a function of frequency of the tone and the bandwidth of the masking sound. The auditory filters have been shown (Glasberg & Moore, 1986) to be wider for listeners with sensorineural impairment. In a recent study (Christensen et al., 2017) it was demonstrated on group basis that the distortion product stimulus ratio that provided the strongest 2f1-f2 component at low frequencies, had a strong correlation to the theoretical relation between frequency and auditory filter bandwidth (described by the Equivalent Rectangular Bandwidth, ERB (Glasberg & Moore, 1990)). The purpose of the present study is to test if a similar correlation exists on an individual basis at normal audiometric frequencies. The optimal 2f1-f2 (L1/L2=65/45 dB SPL) DPOAE ratio is determined using a custom-made measurement system programmed in MATLAB. The auditory filters are determined using notched-noise method in a two alternative forced choice experiment with noise levels at 40 dB SPL/Hz. Optimal ratios and auditory filters are determined at 1, 2 and 4 kHz for 10 young normal-hearing subjects.