Cochlear Implantation Improves Spatial Release From Masking and Restores Localization Abilities in Single-sided Deaf Patients

• Published in: Otology & neurotology Vol. 37; no. 6; p. 658
• Main Authors: Grossmann, Wilma, Brill, Stefan, Moeltner, Alexander, Mlynski, Robert, Hagen, Rudolf, Radeloff, Andreas
• Format: Journal Article
• Language: English
• Published: United States 01.07.2016
• Subjects: Adult; Cochlear Implantation; Cochlear Implants; Female; Hearing; Hearing Loss, Unilateral - surgery; Hearing Tests; Humans; Male; Middle Aged; Noise; Young Adult
• ISSN: 1537-4505
• DOI: 10.1097/MAO.0000000000001043

Adult patients with acquired single-sided deafness (SSD) benefit from binaural hearing after cochlear implantation (CI). To spatially separate the signal of interest from noise is of utmost importance for the speech understanding in challenging listening situations. This ability, however, largely depends on binaural hearing. CI in acquired SSD restores hearing on the deaf ear. This study intended to test, if this is accompanied by a restoration of binaural functions of the auditory system. Eleven CI users with SSD and normal hearing to mild sensorineural hearing loss in the contralateral ear participated in this study. Speech reception thresholds (SRT) were obtained using the Oldenburg Sentence Test (OLSA) sentence test in competing two talker babble noise. To evaluate spatial release from masking, seven spatial configurations of speech and noise were used in a free field setup: noise originated from 0 degree, ±45 degrees and ±90 degrees incidence angles, whereas speech was either presented from the front or ±90 degrees. In addition, localization ability in the frontal horizontal plane was assessed with a 1 s Comité Consultatif International Téléphonique et Télégraphique (CCITT) noise stimulus using an array of nine equally spaced loudspeakers. All tests were conducted in acoustic normal hearing ear alone (AH) and aided conditions. In conditions with spatially separated signal and noise sources, significant benefit of the aided over the AH condition was observed, even when noise was presented from the AH side. Localization ability significantly improved in the aided condition. The present data demonstrates that spatial release from masking can be restored in patients with SSD using a cochlear implant.