Cochlear Implantation in Cases of Single-Sided Deafness

Subjects were asked to identify the noise source from an 11-speaker array with the cochlear implant on versus off. The intensity level of the stimulus was randomly varied (10 dB around 70 dB SPL) to limit the listener relying on level effects. Responses at each intensity level (i.e., 60, 70, and 80 dB SPL) for a given sound source (speaker) were combined (averaged). Results are reported in adjusted constant error. A lower value indicates better performance. Results are compared during the first year of cochlear implant use.

Time frame: Intervals within the first year of device use (e.g., preoperative, and 1-, 3-, 6-, 9-, and 12-months post-activation)

Population: Three participants in the asymmetric hearing loss group did not complete the 9-month interval. One participant in the asymmetric hearing loss group withdrew from the study prior to the 12-month interval.

Subjects were asked to identify the noise source from an 11-speaker array with the cochlear implant on versus off. The intensity level of the stimulus was randomly varied (10 dB around 70 dB SPL) to limit the listener relying on level effects. Responses at each intensity level (i.e., 60, 70, and 80 dB SPL) for a given sound source (speaker) were combined (averaged). Results are reported in constant error. A lower value indicates better performance. Results are compared during the first year of cochlear implant use.

Time frame: Intervals within the first year of device use (e.g., preoperative, and 1-, 3-, 6-, 9-, and 12-months post-activation)

Population: Three participants in the asymmetric hearing loss group did not complete the 9-month interval. One participant in the asymmetric hearing loss group withdrew from the study prior to the 12-month interval.

Subjects were asked to identify the noise source from an 11-speaker array with the cochlear implant on versus off. The intensity level of the stimulus was randomly varied (10 dB around 70 dB SPL) to limit the listener relying on level effects. Responses at each intensity level (i.e., 60, 70, and 80 dB SPL) for a given sound source (speaker) were combined (averaged). Results are reported in root-mean-squared (RMS) error. A lower value indicates better performance. Results are compared during the first year of cochlear implant use.

Time frame: Intervals within the first year of device use (e.g., preoperative, and 1-, 3-, 6-, 9-, and 12-months post-activation)

Population: Three participants in the asymmetric hearing loss group did not complete the 9-month interval. One participant in the asymmetric hearing loss group withdrew from the study prior to the 12-month interval.

Subjects were asked to identify the noise source from an 11-speaker array with the cochlear implant on versus off. The intensity level of the stimulus was randomly varied (10 dB around 70 dB SPL) to limit the listener relying on level effects. Responses at each intensity level (i.e., 60, 70, and 80 dB SPL) for a given sound source (speaker) were combined (averaged). Results are reported in variable error. A lower value indicates better performance. Results are compared during the first year of cochlear implant use.

Time frame: Intervals within the first year of device use (e.g., preoperative, and 1-, 3-, 6-, 9-, and 12-months post-activation)

Population: Three participants in the asymmetric hearing loss group did not complete the 9-month interval. One participant in the asymmetric hearing loss group withdrew from the study prior to the 12-month interval.

Results on recorded speech perception materials: sentence recognition in noise with the target (speaker) and the 10-talker masker from the front speaker. Scored as the percent correctly repeated.

Time frame: Intervals within the first year of device use (e.g., preoperative, and 1-, 3-, 6-, 9-, and 12-months post-activation)

Population: Three participants with asymmetric hearing loss did not complete the 9-month interval. One participant with asymmetric hearing loss withdrew from the study prior to the 12-month interval. Four participants were tested at a different signal-to-noise ratio.

Results on recorded speech perception materials: sentence recognition in noise with the target (speaker) from the front and the 10-talker masker 90 degrees towards the poorer hearing ear (implanted ear). Scored as the percent correctly repeated.

Time frame: Intervals within the first year of device use (e.g., preoperative, and 1-, 3-, 6-, 9-, and 12-months post-activation)

Population: Three participants with asymmetric hearing loss did not complete the 9-month interval. One participant with asymmetric hearing loss withdrew from the study prior to the 12-month interval. Four participants were tested at a different signal-to-noise ratio.

Results on recorded speech perception materials: sentence recognition in noise with the target (speaker) and the 4-talker masker from the front speaker. Scored as dB signal-to-noise ratio that the listener gets 50% speech understanding. Lower numbers indicate better performance (range -7.5 to 23.5 dB SNR).

Time frame: Intervals within the first year of device use (e.g., preoperative, and 1-, 3-, 6-, 9-, and 12-months post-activation)

Population: Three participants with asymmetric hearing loss did not complete the 9-month interval. One participant with asymmetric hearing loss withdrew from the study prior to the 12-month interval. Four participants were tested at a different signal-to-noise ratio.

Results on recorded speech perception materials: sentence recognition in noise with the target (speaker) from the front and the 4-talker masker 90 degrees towards the normal/better hearing ear. Scored as dB signal-to-noise ratio that the listener gets 50% speech understanding. A lower value indicates better performance (range -7.5 to 23.5 dB SNR).

Time frame: Intervals within the first year of device use (e.g., preoperative, and 1-, 3-, 6-, 9-, and 12-months post-activation)

Population: Three participants with asymmetric hearing loss did not complete the 9-month interval. One participant with asymmetric hearing loss withdrew from the study prior to the 12-month interval. Four participants were tested at a different signal-to-noise ratio.

Results on recorded speech perception materials: sentence recognition in noise with the target (speaker) from the front and the 4-talker masker 90 degrees towards the poorer hearing ear (implanted ear). Scored as dB signal-to-noise ratio that the listener gets 50% speech understanding. Lower values indicate better performance (range -7.5 to 23.5 dB SNR).

Time frame: Intervals within the first year of device use (e.g., preoperative, and 1-, 3-, 6-, 9-, and 12-months post-activation)

Population: Three participants with asymmetric hearing loss did not complete the 9-month interval. One participant with asymmetric hearing loss withdrew from the study prior to the 12-month interval. Four participants were tested at a different signal-to-noise ratio.

Results on recorded speech perception materials: sentence recognition in noise with the target (speaker) from the front and the 10-talker masker 90 degrees towards the normal/better hearing ear. Scored as the percent correctly repeated.

Time frame: Intervals within the first year of device use (e.g., preoperative, and 1-, 3-, 6-, 9-, and 12-months post-activation)

Population: Three participants with asymmetric hearing loss did not complete the 9-month interval. One participant with asymmetric hearing loss withdrew from the study prior to the 12-month interval. Four participants were tested at a different signal-to-noise ratio.

Subjects completed subjective questionnaires in order to evaluate the perceived benefits of cochlear implantation. For the Abbreviated Profile of Hearing Aid Benefit, participants rank their perceived difficulty on a scale of 1-99, with lower values indicate less perceived difficulty. The global score is average response across questions for the ease of communication, reverberation, and effectiveness in background noise subscales.

Time frame: Intervals within the first year of device use (e.g., preoperative, and 1-, 3-, 6-, 9-, and 12-months post-activation)

Population: Three participants in the asymmetric hearing loss group did not complete the 9 month interval. One participant in the asymmetric hearing loss group withdrew from the study prior to the 12-month interval.

Subjects completed subjective questionnaires in order to evaluate the perceived benefits of cochlear implantation. For the Speech, Spatial, and Qualities of hearing questionnaire, participants rank their perceived abilities on a scale of 0-10. Higher values indicate more perceived abilities. Results are reported as the total score at each interval, which is the average of the responses from all questions for the questionnaire.

Time frame: Intervals within the first year of device use (e.g., preoperative, and 1-, 3-, 6-, 9-, and 12-months post-activation)

Population: Three participants in the asymmetric hearing loss group did not complete the 9 month interval. One participant in the asymmetric hearing loss group withdrew from the study prior to the 12-month interval.

Subjects completed subjective questionnaires to order to evaluate the perceived benefits of cochlear implantation. For the Tinnitus Handicap Inventory, participants rank their perceived tinnitus severity on a scale of 0-100, with lower values indicate less tinnitus severity. Responses across all questions are summed to derive the total score.

Time frame: Intervals within the first year of device use (e.g., preoperative, and 1-, 3-, 6-, 9-, and 12-months post-activation)

Population: Three participants in the asymmetric hearing loss group did not complete the 9 month interval. One participant in the asymmetric hearing loss group withdrew from the study prior to the 12-month interval.

Results on recorded speech perception materials: monosyllabic (Consonant-Nucleus-Consonant) words in quiet during the first year of device use.

Time frame: Intervals within the first year of device use (e.g., preoperative, and 1-, 3-, 6-, 9-, and 12-months post-activation)

Population: Three participants with asymmetric hearing loss did not complete the 9-month interval. One participant with asymmetric hearing loss withdrew from the study prior to the 12-month interval.

Results on recorded speech perception materials: aided word recognition. Recorded 50-word CNC words were evaluated preoperatively with a conventional hearing aid. Performance was compared to the CI alone at the 12 month interval. A paired samples t-test compared the performance with the two devices. Percent correct data were converted to rationalized arcsine units (RAU) prior to data analysis to control for potential floor or ceiling effects (e.g., scores \<20%).

Time frame: preoperative interval and 12 month post-activation interval

Population: One asymmetric hearing loss participant withdrew prior to the 12-month interval.

Subjects were asked to identify the noise source from an 11-speaker array with the cochlear implant on versus with a bone-conduction device. The intensity level of the stimulus was randomly varied (10 dB around 70 dB SPL) to limit the listener relying on level effects. Responses at each intensity level (i.e., 60, 70, and 80 dB SPL) for a given sound source (speaker) were combined (averaged). Results are reported in root-mean-squared (RMS) error. A lower value indicates better performance.

Time frame: Intervals within the first year of device use (e.g., preoperative, and 1-, 3-, 6-, 9-, and 12-months post-activation)

Population: Three participants in the asymmetric group did not complete testing at the 9-month interval. One participant did not complete testing with the CI on at the 12-month interval. Three participants did not complete testing in the with the bone conduction device at the 12-month interval.

Subjects were asked to identify the noise source from an 11-speaker array with the bone-conduction device on versus off. The intensity level of the stimulus was randomly varied (10 dB around 70 dB SPL) to limit the listener relying on level effects. Responses at each intensity level (i.e., 60, 70, and 80 dB SPL) for a given sound source (speaker) were combined (averaged). Results are reported in root-mean-squared (RMS) error. A lower value indicates better performance. Subjects in the control group were implantable bone-conduction device recipients (alternative treatment option) with at least 12 months of listening experience with their implanted bone-conduction device. Participants completed the task with their device on and off.

Time frame: Assessment completed after 12 months of implantable bone-conduction listening experience

Recorded AzBio sentences in a 10-talker masker were evaluated in 2 conditions: 1) bone-conduction device at the preoperative interval and 2) with the cochlear implant (CI) at the 12-month post-activation period. A paired samples t-test compared the performance with the two devices. Percent correct data were converted to rationalized arcsine units (RAU) prior to data analysis.

Time frame: preoperative interval and 12 month post-activation interval

Population: One participant with asymmetric hearing loss withdrew from the study prior to the 12-month interval. Seven participants were tested at a different signal-to-noise ratio at the preoperative interval. Four participants were tested at a different signal-to-noise ratio.

Recorded AzBio sentences in a 10-talker masker were evaluated in 2 conditions: 1) bone-conduction device at the preoperative interval and 2) with the cochlear implant (CI) at the 12-month post-activation period. A paired samples t-test compared the performance with the two devices. Percent correct data were converted to rationalized arcsine units (RAU) prior to data analysis.

Time frame: preoperative interval and 12 month post-activation interval

Population: One participant with asymmetric hearing loss withdrew from the study prior to the 12-month interval. Seven participants were tested at a different signal-to-noise ratio at the preoperative interval. Four participants were tested at a different signal-to-noise ratio.

Recorded AzBio sentences in a 10-talker masker were evaluated in 2 conditions: 1) bone-conduction device at the preoperative interval and 2) with the cochlear implant (CI) at the 12-month post-activation period. A paired samples t-test compared the performance with the two devices. Percent correct data were converted to rationalized arcsine units (RAU) prior to data analysis.

Time frame: preoperative interval and 12 month post-activation interval

Population: One participant with asymmetric hearing loss withdrew from the study prior to the 12-month interval. Seven participants were tested at a different signal-to-noise ratio at the preoperative interval. Four participants were tested at a different signal-to-noise ratio.

Recorded BKB sentences in a 4-talker masker were evaluated in 2 conditions: 1) bone-conduction device at the preoperative interval and 2) with the cochlear implant (CI) at the 12-month post-activation period. A paired samples t-test compared the performance with the two devices. Results are reported in dB SNR, where a lower value indicates better performance (range -7.5 to 23.5 dB SNR).

Time frame: preoperative interval and 12 month post-activation interval

Population: One asymmetric hearing loss participant withdrew prior to the 12-month interval.

Recorded BKB sentences in a 4-talker masker were evaluated in 2 conditions: 1) bone-conduction device at the preoperative interval and 2) with the cochlear implant (CI) at the 12-month post-activation period. A paired samples t-test compared the performance with the two devices. Results are reported in dB SNR, where a lower value indicates better performance (range -7.5 to 23.5 dB SNR).

Time frame: preoperative interval and 12 month post-activation interval

Population: One asymmetric hearing loss participant withdrew prior to the 12-month interval.

Recorded BKB sentences in a 4-talker masker were evaluated in 2 conditions: 1) bone-conduction device at the preoperative interval and 2) with the cochlear implant (CI) at the 12-month post-activation period. A paired samples t-test compared the performance with the two devices. Results are reported in dB SNR, where a lower value indicates better performance (range -7.5 to 23.5 dB SNR).

Time frame: preoperative interval and 12 month post-activation interval

Population: One asymmetric hearing loss participant withdrew prior to the 12-month interval.

The speech perception (cochlear implant recipients with UHL/SSD) to a control group of implantable bone-conduction device recipients (alternative treatment option). Participants in the control group had at least 12 months of listening experience with their implanted bone-conduction device prior to study participation. Sentence recognition was assessed in a 10-talker masker at 0 dB SNR with the target speech presented from the front and the masker (1) presented from the front (SoNo), (2) presented towards the implanted ear (SoNbc), and (3) presented towards the acoustic ear (SoNnh). Performance was scored as the percent of words correctly repeated, with higher values indicating better performance. The task was completed with the participants listening with their bone-conduction device on versus off.

Time frame: Assessment completed after 12 months of implantable bone-conduction listening experience

Population: Performance on measures of speech perception

The speech perception outcomes in the study population (cochlear implant recipients with UHL/SSD) to a control group of implantable bone-conduction device recipients (alternative treatment option). Participants in the control group had at least 12 months of listening experience with their implanted bone-conduction device prior to study participation. Sentence recognition was assessed in a 4-talker masker with the target speech presented from the front and the masker (1) presented from the front, (2) presented towards the implanted ear, and (3) presented towards the acoustic ear. Performance was scored as the dB SNR when the participant understood 50% correct, with lower values indicating better performance. Participants completed the task with the device on and off.

Time frame: Assessment completed after 12 months of implantable bone-conduction listening experience

Subjects completed subjective questionnaires. For the Abbreviated Profile of Hearing Aid Benefit, participants rank their perceived difficulty on a scale of 1-99, with lower values indicate less perceived difficulty. Results are reported as the average responses for each of the four subscales: ease of communication, reverberation, effectiveness in background noise, and reverberation. The global score is the average response across questions for the ease of communication, reverberation, and effectiveness in background noise subscales. Participants in the control group had at least 12 months of listening experience with their implanted bone-conduction device prior to study participation.

Time frame: Assessment completed after 12 months of implantable bone-conduction listening experience

Subjects completed subjective questionnaires. For the Speech, Spatial, and Qualities of hearing questionnaire, participants rank their perceived abilities on a scale of 0-10. Higher values indicate more perceived abilities. Results are reported as the average responses across questions for each subscale (Speech Hearing, Spatial Hearing, and Qualities of Hearing). Results are also reported as the total score at each interval, which is the average of the responses from all questions for the questionnaire. Participants in the control group had at least 12 months of listening experience with their implanted bone-conduction device prior to study participation.

Time frame: Assessment completed after 12 months of implantable bone-conduction listening experience

Subjects completed subjective questionnaires. For the Abbreviated Profile of Hearing Aid Benefit, participants rank their perceived difficulty on a scale of 1-99, with lower values indicate less perceived difficulty. The global score is the average response across questions for the ease of communication, reverberation, and effectiveness in background noise subscales.

Time frame: preoperative interval, and post-activation intervals (1, 3, 6, 9, and 12 months)

Population: Three participants in the asymmetric hearing loss group did not complete the 9 month interval. One participant in the asymmetric hearing loss group withdrew from the study prior to the 12-month interval.

Subjects completed subjective questionnaires. For the Speech, Spatial, and Qualities of hearing questionnaire, participants rank their perceived abilities on a scale of 0-10. Higher values indicate more perceived abilities. Results are reported as the total score at each interval, which is the average of the responses from all questions for the questionnaire.

Time frame: preoperative interval, and post-activation intervals (1, 3, 6, 9, and 12 months)

Population: Three participants in the asymmetric hearing loss group did not complete the 9 month interval. One participant in the asymmetric hearing loss group withdrew from the study prior to the 12-month interval.

Subjects completed subjective questionnaires. For the Tinnitus Handicap Inventory, participants rank their perceived tinnitus severity on a scale of 0-100, with lower values indicate less tinnitus severity. Responses across all questions are summed to derive the total score.

Time frame: Intervals within the first year of device use (e.g., preoperative, and 1-, 3-, 6-, 9-, and 12-months post-activation)

Population: Three participants in the asymmetric hearing loss group did not complete the 9 month interval. One participant in the asymmetric hearing loss group withdrew from the study prior to the 12-month interval.

Participants completed an adaptive pitch matching task that compared the pitch of acoustic stimulation presented to their normal hearing ear with the perception of stimulation from the cochlear implant. Two stimuli were used: clicks & tones. Pitch perception was evaluated for the 5 most apical electrodes. A normalized score was obtained (normalized score = geometric mean of the responses / electric center frequency of the evaluated electrode); that is, the normalized score = perceived frequency / frequency information presented by the electrode. Results are reported as the averaged normalized score for clicks & tones for each electrode (electrodes 1-5) at each interval (1, 3, 6, and 12 months post-activation). A value of 1.0 indicates the participant perceived the same frequency as the center frequency presented by the electrode. A value \< 1.0 indicates a lower perceived pitch and a value \> 1.0 indicates a higher perceived pitch than the electric frequency information.

Time frame: post-activation period (1, 3, 6, and 12 months post-activation)

Population: 19 of the 20 participants in the single-sided deafness/unilateral hearing loss group elected to complete the pitch matching task on the five most apical electrodes. One participant missed the 1-month and 3-month intervals. Another participant missed the 6-month interval.

Subjects were asked to identify the noise source from an 11-speaker array with a bone-conductive device on versus off. The intensity level of the stimulus was randomly varied (10 dB around 70 dB SPL) to limit the listener relying on level effects. Responses at each intensity level (i.e., 60, 70, and 80 dB SPL) for a given sound source (speaker) were combined. Results are reported in root-mean-squared (RMS) error. A lower value indicates better performance. Results are compared at the preoperative and 12-month post-activation intervals.

Time frame: preoperative and 12-month post-activation intervals.

Population: One participant in the asymmetric group withdrew before the 12-month interval. Two additional participants in the asymmetric hearing loss group did not complete the procedure with the bone-conduction device at the 12-month interval.

Subjects were asked to identify the noise source from an 11-speaker array. The intensity level of the stimulus was randomly varied (10 dB around 70 dB SPL) to limit the listener relying on level effects. Responses at each intensity level (i.e., 60, 70, and 80 dB SPL) for a given sound source (speaker) were combined. Performance was measured with a bone conduction device preoperatively and 12 months post-activation. Overall root-mean-square (RMS) error is the difference between the sound source azimuth and the response azimuth and a lower score indicates more accurate localization of the sound source.

Time frame: preoperative and 12-month intervals

Population: Three participants in the asymmetric hearing loss group did not complete the task at the 12-month interval.

9 participants repeated the pitch perception task at the 12-month interval while listening to the CIS strategy. FS4 & CIS strategies differ in whether or not fine structure cues are provided on the 4 most apical electrodes; there is no difference in the cues provided by electrode 5. An adaptive task compared the pitch of acoustic stimulation presented to the normal hearing ear with the stimulation from the cochlear implant. A normalized score was obtained (normalized score = geometric mean of the responses / electric center frequency of the evaluated electrode); that is, the normalized score = perceived frequency / presented frequency information. Results are reported as the averaged normalized score for clicks & tones for each electrode. A value of 1.0 indicates the perceived frequency was the same as the electric frequency information. A value \< 1.0 indicates a lower perceived pitch and a value \> 1.0 indicates a higher perceived pitch than the electric frequency information.

Time frame: 12-month interval

Population: One participant did not complete testing for electrode 5

Speech recognition in noise with the AzBio sentences in 3 masker conditions (masker from the front, masker towards the better hearing ear, and masker towards the poorer hearing ear) at the preoperative and 12-month intervals in the unaided condition and with a bone-conduction device. Percent correct results were converted to rationalized arcsine units (RAUs) which helps to control for floor and ceiling effects in the perception correct data (e.g., \<20% correct).

Time frame: preoperative interval and 12-month post-activation interval.

Population: All participants in the UHL/SSD group completed the task at 0 dB SNR. Not all participants in the AHL group completed the task at 0 dB SNR.

Speech recognition with a bone-conduction device was compared at the preoperative and 12-month intervals. Performance was evaluated for the AzBio sentences in a 10-talker masker (0 dB SNR) presented with the target and masker from the front, the target from the front and masker to the acoustic hearing, and target from the front and masker towards the affected ear.

Time frame: preoperative and 12-month intervals

Population: Thirteen participants with asymmetric hearing loss completed the task at the preoperative and 12-month intervals at 0 dB SNR.

The unaided hearing thresholds were measured preoperatively and post-operatively/post-activation. Twenty-five participants with SSD or AHL had an unaided threshold at 125 Hz of 80 dB HL or better. Their unaided thresholds were reviewed with respect to hearing preservation. The data from the SSD and AHL group were combined to review hearing preservation with long arrays. The inclusion criteria for the implanted ear were the same for the SSD and AHL groups and all subjects received the same 31.5 mm electrode array.

Time frame: pre-operative, initial activation, and post-activation intervals (1, 3, 6, 9, and 12-months).

Population: Participants in the SSD/UHL and AHL groups that presented with an unaided threshold at 125 Hz of 80 dB HL or better (n=25). A value of 100 dB HL was entered for cases of no response.~Nine participants had a threshold of 95 dB HL or better at initial activation and were reviewed over the post-activation period. Two participants did not complete the 9-month and one participant did not complete the 12-month.