Clinical outcomes with the Kanso™ off-the-ear cochlear implant sound processor

The (in)visibility of deafness: Identity, stigma, quality of life and the potential role of totally implantable cochlear implants

INTRODUCTION

The disclosure of deafness is complex, given the historic and on-going stigma associated with being deaf. The aim of this study was to explore how identity, stigma, and quality of life may be impacted when using cochlear implants (CIs) and totally implantable cochlear implants (TICIs). The physical difference between these two assistive listening devices is significant, given many CI users opt to hide their sound processor behind hair or headwear, in contrast to TICIs (an emerging technology) whereby all components are implanted internally and thus invisible.

METHODS

This qualitative study involved semistructured interviews and demographic questionnaires with 12 adult participants with more than 1 year of experience using their CI. Participants were recruited Australia-wide through community organisations that support deaf and hard-of-hearing individuals. Interview transcripts were analysed thematically, with the themes generated through an inductive process, with consensus generated through group working with three members from the research team.

RESULTS

Four major themes were identified: (1) CI challenges; (2) The importance of social and support networks; (3) Identity and disclosure and (4) Concerns about TICIs. The underlying finding was centred around the construction of deaf identity. Participant attitudes were generally categorised as 'Loud and proud', with the recognition that displaying the CI was an extension of self, something to be proud of, and a means to normalise deafness; or 'Out of sight and out of mind', which sought to minimise the visibility of deafness. While both identities differed in how deafness is disclosed, they are fundamentally related to the same ideas of self-agency and empowerment.

CONCLUSION

TICIs present a novel opportunity-the ability for CI users to control the visibility of their deafness and thus control disclosure. This study explored the impact of stigma and categorised two core identities that CI users construct. Future directions include investigating potential CI candidates, to explore if TICIs may be a facilitator to CI uptake.

PATIENT OR PUBLIC CONTRIBUTION

The semistructured interview guide was developed in consultation with adults with CIs. Feedback led to adjustments and improvement to the interview guide. In addition, F. R. has a lived experience with hearing loss, and C. Y. L. is an executive committee member for a nonprofit charity organisation that supports families that are D/deaf and hard-of-hearing.

Speech Understanding and Subjective Listening Effort in Noise With Different OTEs and Sound Processing Technologies

OBJECTIVE

To determine speech reception thresholds (SRTs) in noise and subjective listening effort (LE) in cochlear implant (CI) recipients for application of three sound processing (SP) technologies with two off-the-ear (OTE) CI sound processors, a fixed moderately directional microphone (Standard), an adaptive directional microphone (Beam), and the spatial noise-reduction setting ForwardFocus, with the Kanso 2 (OTE2), and Beam with the Kanso (OTE1).

STUDY DESIGN

Prospective repeated measures, within-subject design.

SETTING

Single tertiary-referral center.

PATIENTS

Twenty CI recipients with bilateral severe-to-profound sensorineural hearing loss.

MAIN OUTCOME MEASURES

SRTs were assessed in two spatial configurations with frontal speech and noise from 90-180-270 degrees (S0N90-180-270) or from the CI side (S0NCI). SRTs were obtained for sentences of the Oldenburg sentence test presented in International Collegium of Rehabilitative Audiology (ICRA) noise ICRA5-250. LE for speech understanding in noise was evaluated in S0N90-180-270 and assessed in effort scale categorical units (ESCUs) by using Adaptive Categorical Listening Effort Scaling (ACALES). LEs at 5-dB signal-to-noise ratio (SNR) were calculated from fitted psychometric curves.

RESULTS

With OTE2 in S0N90-180-270, SRT with ForwardFocus (-4.28 dB SNR) was better than with Beam (-3.13 dB SNR) and Standard (0.43 dB SNR). ForwardFocus showed lower LE5dB (2.61 ESCU) compared with Beam (4.60 ESCU) and Standard (5.32 ESCU). In a comparison of both OTEs in S0N90-180-270 regarding best-performing SP technology, ForwardFocus with OTE2 yielded a better SRT and better LE5dB than Beam with OTE1 (SRT: -1.70 dB SNR; LE5dB: 4.00 ESCU). With OTE2 in S0NCI, SRT was improved with ForwardFocus (-2.78 dB SNR) compared with Beam (-1.23 dB SNR) and Standard (1.83 dB SNR).

CONCLUSION

With respect to SP technology and OTE, CI recipients experience best SRT and lowest LE in S0N90-180-270 when using ForwardFocus with OTE2. ACALES is feasible for assessing subjective LE in CI recipients.

Speech understanding in noise for cochlear implant recipients using a spatial noise reduction setting in an off the ear sound processor with directional microphones

PURPOSE

Cochlear implant (CI) recipients struggle to hear in competing background noise. ForwardFocus is a spatial noise reduction setting from Cochlear Ltd. (Sydney) that can simultaneously attenuate noise from multiple sources behind the listener. This study assessed hearing performance with ForwardFocus in an off-the-ear (OTE) sound processor.

METHOD

Twenty-two experienced adult CI recipients participated. Speech reception data was collected in fixed noise acutely in the clinic. After three to five weeks take home experience, subjective impressions were recorded, and evaluations were conducted for speech reception in quiet and roving noise.

RESULTS

Group mean speech reception thresholds (SRT) were below 0 dB in two spatially-separated noise test conditions when using ForwardFocus in the OTE sound processor. SRT were -8.5 dB (SD 2.9) in 4-talker babble roving in a rear hemi-field (S0Nrearhemi) and -3.9 dB (SD 3.3) in 12-talker babble presented laterally and behind (S0N3). Results in S0N3 were significantly better with ForwardFocus On (p = 0.0018). Subjective ratings with the OTE were comparable to, or better than, with their walk-in BTE or OTE sound processor.

CONCLUSIONS

ForwardFocus provides significant benefits for speech recognition in competing background noise in an OTE sound processor. These results support clinicians in counselling CI recipients on potential sound processor options to consider.

Cochlear implant aesthetics and its impact on stigma, social interaction and quality of life: a mixed-methods study protocol

INTRODUCTION

Awareness of the benefits of cochlear implants is low, and barriers such as fear of surgery and ongoing rehabilitation have been noted. Perceived stigma associated with hearing loss also plays a key role, with many adults not wanting to appear old or be identified as a person with a disability. In effect, a cochlear implant makes deafness visible. New technologies have led to a smaller external profile for some types of cochlear implants, but qualitative assessments of benefit have not been explored. This study will examine cochlear implant aesthetics and cosmetics, and its impact on perceived stigma, social interactions, communication and quality of life. A particular focus will be the examination of totally implantable device concepts. A secondary aim is to understand what research techniques are best suited and most appealing for cochlear implant recipients, to assist in future study design and data collection methods.

METHODS AND ANALYSIS

This study utilises a mixed-methods design. Three datasets will be collected from each participant with an expected sample size of 10-15 participants to allow for data saturation of themes elicited. Each participant will complete a demographic questionnaire, a quickfire survey (a short concise questionnaire on a topic of research familiarity and preference) and a semi-structured interview. Questionnaire and quickfire survey data will be analysed using descriptive statistics. Interviews will be transcribed and analysed thematically. All participants will be adults with more than 1 year of experience using cochlear implants.

ETHICS AND DISSEMINATION

This study has been granted ethical approval from Macquarie University (HREC: 520211056232432) and meets the requirements set out in the National Statement on Ethical Conduct in Human Research. Study findings will be disseminated widely through international peer-reviewed journal articles, public and academic presentations, plain language summaries for participants and an executive summary for the project funder. This work was supported by Cochlear Limited (Cochlear Ltd). The funder will have no role in conducting or reporting on the study.

Comparison of Speech Recognition in Cochlear Implant Users with Different Speech Processors

BACKGROUND

Speech recognition in noisy environments is a challenge for both cochlear implant (CI) users and device manufacturers. CI manufacturers have been investing in technological innovations for processors and researching strategies to improve signal processing and signal design for better aesthetic acceptance and everyday use.

PURPOSE

This study aimed to compare speech recognition in CI users using off-the-ear (OTE) and behind-the-ear (BTE) processors.

DESIGN

A cross-sectional study was conducted with 51 CI recipients, all users of the BTE Nucleus 5 (CP810) sound processor. Speech perception performances were compared in quiet and noisy conditions using the BTE sound processor Nucleus 5 (N5) and OTE sound processor Kanso. Each participant was tested with the Brazilian-Portuguese version of the hearing in noise test using each sound processor in a randomized order. Three test conditions were analyzed with both sound processors: (i) speech level fixed at 65 decibel sound pressure level in a quiet, (ii) speech and noise at fixed levels, and (iii) adaptive speech levels with a fixed noise level. To determine the relative performance of OTE with respect to BTE, paired comparison analyses were performed.

RESULTS

The paired t-tests showed no significant difference between the N5 and Kanso in quiet conditions. In all noise conditions, the performance of the OTE (Kanso) sound processor was superior to that of the BTE (N5), regardless of the order in which they were used. With the speech and noise at fixed levels, a significant mean 8.1 percentage point difference was seen between Kanso (78.10%) and N5 (70.7%) in the sentence scores.

CONCLUSION

CI users had a lower signal-to-noise ratio and a higher percentage of sentence recognition with the OTE processor than with the BTE processor.

Speech comprehension across multiple CI processor generations: Scene dependent signal processing

OBJECTIVES

In clinical practice, characterization of speech comprehension for cochlear implant (CI) patients is typically administered by a set of suprathreshold measurements in quiet and in noise. This study investigates speech comprehension of the three most recent cochlear implant sound processors; CP810, CP910, and CP1000 (Cochlear Limited). To compare sound processor performance across generations and input dynamic range changes, the state-of-the art signal processing technologies available in each sound processor were enabled. Outcomes will be assessed across a range of stimulation intensities, and finally analyzed with respect to normal hearing listeners.

METHODS

In a prospective study, 20 experienced postlingually deafened CI patients who received a Nucleus CI in the ENT department of the University Hospital of SH in Kiel were recruited. Speech comprehension was measured in quiet at 40, 50, and 65 dBSPL with monosyllabic words as well as by speech reception threshold for two-digit numbers. In noise, speech reception thresholds were measured with the adaptive German matrix test with speech and noise in front.

RESULTS

We found that high levels of open-set speech comprehension are achieved at suprathreshold presentation levels in quiet. However, results at lower test levels have remained mostly unchanged for tested sound processors with default dynamic range. Expanding the lower limit of the acoustic input dynamic range yields better speech comprehension at lower presentation levels. In noise the application of ForwardFocus improves the speech reception. Overall, a continuous improvement for speech perception across three generations of CI sound processors was found.

CONCLUSIONS

Findings motivate further development of signal pre-processing, an additional focus of clinical work on lower stimulation levels, and automation of ForwardFocus.

LEVEL OF EVIDENCE

2.

The Benefit of Remote and On-Ear Directional Microphone Technology Persists in the Presence of Visual Information

BACKGROUND

 Both the Roger remote microphone and on-ear, adaptive beamforming technologies (e.g., Phonak UltraZoom) have been shown to improve speech understanding in noise for cochlear implant (CI) listeners when tested in audio-only (A-only) test environments.

PURPOSE

 Our aim was to determine if adult and pediatric CI recipients benefited from these technologies in a more common environment-one in which both audio and visual cues were available and when overall performance was high.

STUDY SAMPLE

 Ten adult CI listeners (Experiment 1) and seven pediatric CI listeners (Experiment 2) were tested.

DESIGN

 Adults were tested in quiet and in two levels of noise (level 1 and level 2) in A-only and audio-visual (AV) environments. There were four device conditions: (1) an ear canal-level, omnidirectional microphone (T-mic) in quiet, (2) the T-mic in noise, (3) an adaptive directional mic (UltraZoom) in noise, and (4) a wireless, remote mic (Roger Pen) in noise. Pediatric listeners were tested in quiet and in level 1 noise in A-only and AV environments. The test conditions were: (1) a behind-the-ear level omnidirectional mic (processor mic) in quiet, (2) the processor mic in noise, (3) the T-mic in noise, and (4) the Roger Pen in noise.

DATA COLLECTION AND ANALYSES

 In each test condition, sentence understanding was assessed (percent correct) and ease of listening ratings were obtained. The sentence understanding data were entered into repeated-measures analyses of variance.

RESULTS

 For both adult and pediatric listeners in the AV test conditions in level 1 noise, performance with the Roger Pen was significantly higher than with the T-mic. For both populations, performance in level 1 noise with the Roger Pen approached the level of baseline performance in quiet. Ease of listening in noise was rated higher in the Roger Pen conditions than in the T-mic or processor mic conditions in both A-only and AV test conditions.

CONCLUSION

 The Roger remote mic and on-ear directional mic technologies benefit both speech understanding and ease of listening in a realistic laboratory test environment and are likely do the same in real-world listening environments.

The effects of behind-the-ear and off-the-ear sound processors on speech understanding performance in cochlear implant users

OBJECTIVE

The first aim of this study was to compare speech understanding performance in adult cochlear implant users using behind-the-ear and off-the-ear sound processors in quiet and noise. Second, the impact of sound processor microphone location on speech understanding performance was compared.

METHODS

Participants were tested with both types of sound processors in the free field with warble tones, and speech discrimination scores in quiet were obtained. Turkish Matrix Test was used to measure speech understanding in noise with five different loudspeaker settings. Twenty-seven participants of cochlear implants between 16 and 67 years-of-age using behind-the-ear or off-the-ear sound processors were included in the study. The results obtained with two types of sound processors were compared.

RESULTS

Aided free field thresholds were significantly better for the behind-the-ear vs. off-the-ear sound processor. The mean difference was 3.3 dB HL. There was no significant difference in speech discrimination scores in quite between the two processors (p > 0.05). Statistically significant differences were not seen for speech intelligibility in five spatial settings in the Turkish Matrix Test (p > 0.05).

CONCLUSION

Although both types of sound processors had different microphone locations, the outcomes were found to be consistent with previous results in adult users off-the-ear sound processors, demonstrating equivalent speech understanding in quiet and noise.

Is Early Cochlear Implant Device Activation Safe for All on-the-Ear and off-the-Ear Sound Processors?

Background: Cochlear implantation (CI) is an effective treatment option for patients with severe-to-profound hearing loss. When CI first started, it was recommended to wait until at least 4 weeks after the CI surgery for the initial activation because of possible complications. Advances in the surgical techniques and experiences in fitting have made initial activation possible within 24 h. Objectives: To compare the complaints and complications after early activation between behind-the-ear (BTE) and off-the-ear (OTE) sound processors and to show the impact of early activation on the electrode impedance values. Method: CI surgeries performed between March 2013 and July 2018 were retrospectively analyzed from the database. In total, 294 CI users were included in the present study. The impedance measurements were analyzed postoperatively at the initial activation prior to the stimulation, and 4 weeks after the initial activation in the first-month follow-up visit. A customized questionnaire was administered in the first-month follow-up fitting session to caregivers and/or patients who were using CI at least for 6 months. Medical records were also reviewed to identify any postoperative complications. Results: In the early activation group, impedance values were significantly lower than in the control group (p < 0.05) at first fitting. At the first-month follow-up, no significant difference was found between the groups (p > 0.05). The most common side effects were reported to be edema (6.1%) and pain (5.7%) in the early activation group. In patients with OTE sound processors, the rate of side effects such as skin infection, wound swelling, skin hyperemia, and pain was higher than in patients with BTE sound processors; however, a statistical significance was only observed in wound swelling (p = 0.005). Selecting the appropriate magnet was defined as a problem for the OTE sound processors during the initial activation. Conclusion: This study revealed that early activation of CI was clinically safe and feasible in patients with BTE sound processors. When using OTE sound processors, the audiologists should be careful during the activation period and inform patients of possible side effects. The first fitting should be delayed for 4 weeks after CI for OTE sound processors. This current study is the first to report this finding with 5 years of experience in a large cohort.