A Comparison Between Wireless CROS and Bone-anchored Hearing Devices for Single-Sided Deafness: A Pilot Study

Primary outcomes

1. Number of 5 Key Words Within 6 Sentence Lists Repeated Correctly in the Presence of Multitalker Noise

   Time frame: The QuickSIN unaided was administered at baseline, an average of 2 weeks (with CROS or BAHD) and an average of 4 weeks (with opposite device not previously tested).

   One speech-in-noise test (QuickSIN) presented four lists of six pre-recorded sentences at 50 dB hearing level (HL) in soundfield. Multitalker noise was presented together with the target sentence and increased at a fixed number of dB with the completion of each sentence. The multitalker noise was initially presented at 25 dB HL (signal-to-noise ratio - SNR of 25 dB), and increased by 5 dB after each sentence until the multitalker noise was of equal intensity with the final sentence (SNR of 0 dB). In one condition, two lists of sentences were presented to the participant at 0 degrees with the multitalker noise delivered at 90 degrees to the poor ear. In the other condition, two different lists of sentences were presented to the participant at 0 degrees with the multitalker noise delivered at 90 degrees to the better ear. The two scores derived from the two different lists of sentences presented within each condition were averaged. A low score indicates better performance.

2. Percentage of Words Recognized

   Time frame: Word recognition testing (unaided) occurred at baseline, an average of 2 weeks (with CROS or BAHD) and an average of 4 weeks (with opposite device not previously tested)..

   Word recognition was tested with the recorded version of the Central Institute for the Deaf (CID) W-22 (Auditec of St. Louis), with a different list of 25 monosyllabic words presented at 50 dB HL in three randomized listening conditions. In the first condition, one list was presented at 50 dB HL at 90 degrees to the poor ear in quiet. In the second condition, the words were presented at 50 dB HL at 0 degrees while multitalker noise was presented at 45 dB HL at 90 degrees to the poor ear. In the final condition, the words were presented at 50 dB HL at 0 degrees while multitalker noise was delivered at 45 dB HL at 90 degrees to the better ear.

3. Speech Spatial Qualities Questionnaire (SSQ)

   Time frame: Administered at the end of a 2 week trial with the CROS and at the end of a 2 week use of the BAHD.

   The Speech Spatial Qualities Questionnaire (SSQ) was given to assess the self-perceived benefits provided by the device that was worn the previous 2 weeks. The SSQ requires participants to rate their perceived hearing ability for 49 scenarios using a 10-point scale, ranging from 0 ("Not at all") to 10 ("Perfectly"). A score higher than 0 for each listening scenario shows some benefit of the device, while a score of 10 indicates the device was extremely beneficial. Therefore, a lower score indicated poorer self-perceived benefit from the device (representing a worse outcome), while a higher score indicated greater self-perceived benefit from the device (representing a better outcome). To obtain individual scores for the SSQ questionnaire, the ratings for each listening scenario were summed. The mean, minimum and maximum scores for each subscale of the SSQ across all participants were also determined.