Cochlear Implants (CI) are now a well-accepted treatment for individuals with severe to profound hearing impairment. Compared to using one CI, bilateral CIs are known to provide access to some of the benefits of binaural hearing like improved speech understanding in noise (primarily due to headshadow), improved localization, reduced stress and fatigue, and improved quality of life (e.g., Dunn et al. 2012, Litovsky et al. 2012, Härkönen et al. 2016, Reeder et al. 2014, Agrawal 2008). However, a number of CI recipients are unable to or choose not to be implanted bilaterally for many reasons. Those with acoustic hearing in the contralateral ear can benefit significantly by using a hearing aid in that ear (bimodal hearing) (Ching et el. 2006, Dorman and Gifford 2010, Dorman et al. 2015, Dunn et al. 2005, Firszt et al. 2012, Illg et al. 2014, Farinetti et al. 2015).
Unilateral CI recipients do not have access to advantages of bilateral and bimodal hearing. In addition to reduced speech understanding in noise, especially when the speech source is located towards the non-CI, they can also experience increased stress and fatigue. Studies have shown that a CROS device, when worn on the contralateral, non-implanted ear, can help overcome speech understanding deficits due to head-shadow. The effect of such technology on quality of life of the CI recipient and their frequent communication partners has not been evaluated over an extended duration of use.
Study methodology:
Fourteen unilateral CI recipients will participate in this study. Testing will be conducted at the University of Utah Hospital ENT clinic. The study will comprise of 2 clinic visits separated by a take-home phase of 6 months. A designated FCP will be a part of each study visit, preferably.
Following are the test measures for CI recipients:
* Questionnaires
* Data logs
* Pure-tone audiometry
* Speech intelligibility
Following are the test measures for FCPs:
• Questionnaires
Speech testing will be conducted in a sound booth with a two speaker set-up (± 90°). AZBio sentences (Spahr et al., 2012) presented at 65 dB A will be the target stimuli. The interferer will be a multi-talker babble. The babble will be presented at an individualized level for each participant where their performance in noise in SCROS(Off)NCI configuration is half of their performance in quiet in SCROS(Off) configuration.
Study devices: For speech testing in the sound booth, a study Naida CI Q90 sound processor will be used. For the take-home phase, recipients will use their own Naida CI processor (Q70 or Q90). A Naida Link CROS will also be used for sound-booth testing as well as the take-home phase.
Workflow:
After recruiting, following will be mailed to the participants to be completed prior to the study visit and hand carried to visit 1:
For each CI subject:
(i) Informed consent form (ii) APS-SSD (Schafer et al, 2013, modified by H. Snapp, 2017) (iii) Nijmegen questionnaire (adapted from Hinderink et al, 2000)
For each CI subject's frequent communication partner:
(i) Informed consent form (ii) SOS-HEAR
