European Archives of Oto-Rhino-Laryngology

, Volume 272, Issue 9, pp 2213–2219 | Cite as

Clinical effectiveness of wireless CROS (contralateral routing of offside signals) hearing aids

  • Nam-Gyu Ryu
  • Il Joon Moon
  • Hayoung Byun
  • Sun Hwa Jin
  • Heesung Park
  • Kyu-Sun Jang
  • Yang-Sun ChoEmail author


This study evaluated the clinical effectiveness of wireless contralateral routing of offside signals hearing aids (CROS) in patients with severe to profound unilateral sensorineural hearing loss (USNHL). Twenty-one patients with USNHL were enrolled in this prospective study. The change of subjective satisfaction was evaluated using three questionnaires (K-HHIE, K-IOI-HA, K-SSQ). Changes in objective measurements were evaluated with sound localization test (SLT) and hearing in noise test (HINT). These tests were performed at pre-CROS fitting, 2 and 4 weeks after use of CROS. Subjects were grouped according to the age: young (<40 years) vs. old (≥40 years) group. The average K-HHIE and K-SSQ scores significantly improved with the use of CROS. SLT result revealed that hit rate and error degree improved in the young group and lateralization ability improved in both groups. In quiet environments, the reception threshold for speech also indicated a significant benefit in the young group. When the noise was presented to the normal ear, HINT revealed benefit of CROS, while loss of performance with CROS use was significant when noise was presented to the impaired ear. Wireless CROS provided increased satisfaction and overall improvement of localization and hearing. Although true binaural hearing cannot be obtained, CROS is a practical option for rehabilitation of USNHL.


Unilateral hearing loss CROS Sound localization Hearing in noise test 


Conflict of interest

None of the authors have any conflict of interest to disclose.

Financial disclosure

This study was supported by a grant of the Korean Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (HI12C1460).


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Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Nam-Gyu Ryu
    • 1
  • Il Joon Moon
    • 1
  • Hayoung Byun
    • 1
  • Sun Hwa Jin
    • 1
  • Heesung Park
    • 1
  • Kyu-Sun Jang
    • 1
  • Yang-Sun Cho
    • 1
    Email author
  1. 1.Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical CentreSungkyunkwan University School of MedicineSeoulKorea

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