CITEC researchers developing diagnostic system at Bielefeld University
Sound source localization is a component of hearing that is difficult to examine with conventional hearing tests. Dr. Thomas Hermann, from the Cluster of Excellence CITEC has developed a system that tests spatial hearing in a natural hearing situation, and can later be used for training. This new diagnostic system was developed together with partners from the Klinikum Bielefeld Mitte (Bielefeld Central Clinic), and is now being further developed in cooperation with the Katholisches Klinikum (Catholic Clinic) of the Ruhr-University Bochum. Beginning on Thursday (13.12.2018), testing started at the Bochum clinic and it may be used as a therapy for patients with hearing impairments. 
The “audio ring” is made of speakers and simulates a real hearing situation. In this case, the situation is the sounds of a café – music, conversation, clatter – and a noise, such as a snapping sound. The patient stands or sits in the middle of the circle of speakers and locates the direction from which the snapping sound is coming from. The individual then marks the location they have perceived on a tablet PC.
“With the software that goes with this system, which we also developed at CITEC, the audio ring serves as a new diagnostic system,” says Dr. Thomas Hermann, who heads the Ambient Intelligence research group at the Cluster of Excellence CITEC at Bielefeld University. “Our studies demonstrated how and where people with hearing difficulties on one side are able to locate sounds with less precision than those with two healthy ears. Our findings also showed that head movements play a decisive role in spatial positioning.” This means that moving one’s head enabled the listener to better locate the sounds – whether or not they had a hearing impairment.
The audio ring at the CITEC Building has a diameter of four meters and consists of 16 speakers on a ring-shaped truss. Another ring with eight speakers is mounted above this. The height of the entire system can be adjusted. “This system is too big for diagnostics in hospital settings. For this reason, we also created a portable ring system that fits in a bag,” says Hermann. The spatial hearing system for the portable case is made with smaller speakers. The portable ring, when fully assembled, has a diameter of 2,5 meters. This diagnostic system is now to be assessed in a first test phase at the Catholic Hospital of the Ruhr-University Bochum.
“The audio ring is an example of how technology from the research setting can be put into use in the lives of affected patients,” says Dr. Martin Lehmann, an ear, nose, and throat doctor at the Bochum clinic. “We expect that we will also be able to use this system in the future for hearing rehabilitation with our patients.”
“Just as with learning vocabulary words, spatial hearing can also be trained. For this, stimuli can be presented more frequently from directions where the patient has problems locating the sound.” A goal here is to motivate patients to have fun while performing their hearing exercises. “We envision a practical and intuitive system, which would also allow for hearing training to be done at home,” says Hermann. “Sounds could be linked to speech comprehension to make for a proper hearing game.”
Dr. Thomas Hermann, Bielefeld University
Cluster of Excellence Cognitive Interaction (CITEC)
Telephone: 0521 106-12140
Email: thermann@techfak.uni-bielefeld.de