Retrospective CI532 Hearing Performance

Primary outcomes

1. Change From Pre-operative (Daily Listening Condition) Baseline Speech Understanding in Quiet at 6 Months Post-operative (Best Aided Conditions).

   Time frame: pre-operatively and at 6 months post-operatively

   Is tested using the centre's clinical routine speech tests. Participants are listening in their normal hearing configuration: often with acoustic hearing aids in both ears preoperatively, an implant in one ear and hearing aid in the opposite, or using two implants, one in each ear postoperatively. All centres used Freiburger German monosyllable lists. Recorded lists of everyday words are presented to participants at 65 dB SPL (loud conversational speech level) from loudspeakers and participants repeat back what they hear. Lists are scored as a percentage correct words, with two lists being used per condition to represent speech understanding in quiet.

2. Change From Pre-operative (Daily Listening Condition) Baseline Speech Understanding in Noise at 6 Months Post-operative (Best Aided Conditions).

   Time frame: pre-operatively and at 6 months post-operatively

   Is tested using the centre's clinical routine speech tests. Participants are listening in their normal hearing configuration: often with acoustic hearing aids in both ears preoperatively, an implant in one ear and hearing aid in the opposite, or using two implants, one in each ear postoperatively. Centres used different types of speech in noise testing. Lists of sentences were presented in competing background noise. An adaptive procedure is used such that after each sentence is presented the speech level is decreased if >50% of the words are correctly repeated in the sentence, or increased if otherwise. The test result is the mean signal-to-noise ratio of the last eight presentations. An average of two lists is used as the result representing the signal-to-noise ratio that gives 50% sentence understanding.

3. Percentage of Participants Showing Post-operative Improvement in the Ipsilateral Ear in Quiet.

   Time frame: pre-operatively and at 6 months post-operatively

   Is tested using the centre's clinical routine speech. Participants are listening using only the ear which was treated using hearing aid preoperatively and the implant postoperatively. All centres used Freiburger German monosyllable lists. Recorded lists of everyday words are presented to participants at 65 dB SPL (loud conversational speech level) from loudspeakers and participants repeat back what they hear. Lists are scored as a percentage correct words, with two lists being used per condition to represent speech understanding in quiet.

4. Percentage of Participants Showing Post-operative Improvement in Best Aided Condition in Quiet

   Time frame: Pre-operatively and at 6 months post-operatively

   Is tested using the centre's clinical routine speech. Participants are listening in their normal hearing configuration: often with acoustic hearing aids in both ears preoperatively, an implant in one ear and hearing aid in the opposite, or using two implants, one in each ear postoperatively. All centres used Freiburger German monosyllable lists. Recorded lists of everyday words are presented to participants at 65 dB SPL (loud conversational speech level) from loudspeakers and participants repeat back what they hear. Lists are scored as a percentage correct words, with two lists being used per condition to represent speech understanding in quiet.

5. Percentage of Participants Showing Post-operative Improvement in the Ipsilateral Ear in Noise.

   Time frame: Pre-operatively and at 6 months post-operatively

   Is tested using the centre's clinical routine speech. Participants are listening using only the ear which was treated using hearing aid preoperatively and the implant postoperatively. Centres used different types of speech in noise testing. Lists of sentences were presented in competing background noise. In some cases the noise level was fixed at 10 dB signal-to-noise ratio, and the percentage of words correctly repeated was recorded (over two lists). Alternatively, an adaptive procedure is used such that after each sentence is presented the speech level is decreased if >50% of the words are correctly repeated in the sentence, or increased if otherwise. The test result is the mean signal-to-noise ratio of the last eight presentations. An average of two lists is used as the result representing the signal-to-noise ratio that gives 50% sentence understanding.

6. Percentage of Participants Showing Post-operative Improvement in Best Aided Condition in Noise.

   Time frame: Pre-operatively and at 6 months post-operatively

   Is tested using the centre's clinical routine speech. Participants are listening in their normal hearing configuration: often with acoustic hearing aids in both ears preoperatively, an implant in one ear and hearing aid in the opposite, or using two implants, one in each ear postoperatively. Centres used different types of speech in noise testing. Lists of sentences were presented in competing background noise. In some cases the noise level was fixed at 10 dB signal-to-noise ratio, and the percentage of words correctly repeated was recorded (over two lists). Alternatively, an adaptive procedure is used such that after each sentence is presented the speech level is decreased if >50% of the words are correctly repeated in the sentence, or increased if otherwise. The test result is the mean signal-to-noise ratio of the last eight presentations. An average of two lists is used as the result representing the signal-to-noise ratio that gives 50% sentence understanding.