Benefits in noise from sound processor upgrade in thirty-three cochlear implant users for more than 20 years

Predicting Matrix Test Effectiveness for Evaluating Auditory Performance in Noise Using Pure-Tone Audiometry and Speech Recognition in Quiet in Cochlear Implant Recipients

INTRODUCTION

Auditory performance in noise of cochlear implant recipients can be assessed with the adaptive Matrix test (MT); however, when the speech-to-noise ratio (SNR) exceeds 15 dB, the background noise has any negative impact on the speech recognition. Here, we aim to evaluate the predictive power of aided pure-tone audiometry and speech recognition in quiet and establish cut-off values for both tests that indicate whether auditory performance in noise can be assessed using the Matrix sentence test in a diffuse noise environment.

METHODS

Here, we assessed the power of pure-tone audiometry and speech recognition in quiet to predict the response to the MT. Ninety-eight cochlear implant recipients were assessed using different sound processors from Advanced Bionics (n = 56) and CochlearTM (n = 42). Auditory tests were performed at least 1 year after cochlear implantation or upgrading the sound processor to ensure the best benefit of the implant. Auditory assessment of the implanted ear in free-field conditions included: pure-tone average (PTA), speech discrimination score (SDS) in quiet at 65 dB, and speech recognition threshold (SRT) in noise that is the SNR at which the patient can correctly recognize 50% of the words using the MT in a diffuse sound field.

RESULTS

The SRT in noise was determined in 60 patients (61%) and undetermined in 38 (39%) using the MT. When cut-off values for PTA <36 dB and SDS >41% were used separately, they were able to predict a positive response to the MT in 83% of recipients; using both cut-off values together, the predictive value reached 92%.

DISCUSSION

As the pure-tone audiometry is standardized universally and the speech recognition in quiet could vary depending on the language used; we propose that the MT should be performed in recipients with PTA <36 dB, and in recipients with PTA >36 dB, a list of Matrix sentences at a fixed SNR should be presented to determine the percentage of words understood. This approach should enable clinicians to obtain information about auditory performance in noise whenever possible.

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.

Value of patient-reported outcome measures for evaluating the benefit of speech processor upgrading in patients with cochlear implants

BACKGROUND

Patients with a cochlear implant (CI) should be evaluated for a new speech processor every 6 years. The aim of this analysis was to assess the subjective and audiological benefit of upgrades.

METHODS

Speech understanding and subjective benefit were analyzed in 99 patients with the old and the new speech processor after 4 weeks of wearing. Speech understanding was assessed using the Freiburg monosyllabic test in quiet (FBE) at 65 dB and 80 dB, and the Oldenburg Sentence Test (OLSA) at 65 dB noise with adaptive speech sound level. The Abbreviated Profile of Hearing Aid Benefit (APHAB) was used to assess subjective hearing impairment, and the Audio Processor Satisfaction Questionnaire (APSQ) was used to assess subjective satisfaction.

RESULTS

The speech processor upgrade resulted in a significant improvement of speech understanding in quiet at 65 dB (mean difference 8.9 ± 25.9 percentage points, p < 0.001) and 80 dB (mean difference 8.1 ± 29.7 percentage points, p < 0.001) and in noise (mean difference 3.2 ± 10.7 dB signal-to-noise ratio [S/N], p = 0.006). Using the APHAB, a significant improvement (mean difference 0.07 ± 0.16, p < 0.001) in hearing impairment was demonstrated in all listening situations. The APSQ showed significantly higher patient satisfaction with the new speech processor (mean difference 0.42 ± 1.26, p = 0.006). A comparative assessment of the benefit based on subjective and speech audiometric results identified a proportion of patients (35-42%) who subjectively benefited from the upgrade but had no measurable benefit based on speech audiometry.

CONCLUSION

There was a significant improvement in audiologically measurable and subjectively reflected speech understanding and patient satisfaction after the upgrade. In patients with only a small improvement in audiologically measurable speech understanding, the subjective benefit should also be assessed with validated measurement instruments in order to justify an upgrade to the payers in the health sector.

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.

[Value of patient-reported outcome measures for evaluating the benefit of speech processor upgrading in patients with cochlear implants. German version]

BACKGROUND

Patients with a cochlear implant (CI) should be evaluated for a new speech processor every 6 years. The aim of this analysis was to assess the subjective and audiological benefit of upgrades.

METHODS

Speech understanding and subjective benefit were analyzed in 99 patients with the old and the new speech processor after 4 weeks of wearing. Speech understanding was assessed using the Freiburg monosyllabic test in quiet (FBE) at 65 dB and 80 dB, and the Oldenburg Sentence Test (OLSA) at 65 dB noise with adaptive speech sound level. The Abbreviated Profile of Hearing Aid Benefit (APHAB) was used to assess subjective hearing impairment, and the Audio Processor Satisfaction Questionnaire (APSQ) was used to assess subjective satisfaction.

RESULTS

The speech processor upgrade resulted in a significant improvement of speech understanding in quiet at 65 dB (mean difference 8.9 ± 25.9 percentage points, p < 0.001) and 80 dB (mean difference 8.1 ± 29.7 percentage points, p < 0.001) and in noise (mean difference 3.2 ± 10.7 dB signal-to-noise ratio [S/N], p = 0.006). Using the APHAB, a significant improvement (mean difference 0.07 ± 0.16, p < 0.001) in hearing impairment was demonstrated in all listening situations. The APSQ showed significantly higher patient satisfaction with the new speech processor (mean difference 0.42 ± 1.26, p = 0.006). A comparative assessment of the benefit based on subjective and speech audiometric results identified a proportion of patients (35-42%) who subjectively benefited from the upgrade but had no measurable benefit based on speech audiometry.

CONCLUSION

There was a significant improvement in audiologically measurable and subjectively reflected speech understanding and patient satisfaction after the upgrade. In patients with only a small improvement in audiologically measurable speech understanding, the subjective benefit should also be assessed with validated measurement instruments in order to justify an upgrade to the payers in the health sector.

The COVID-19 pandemic and upgrades of CI speech processors for children: part II-hearing outcomes

PURPOSE

To gauge the benefits to children of upgrading speech processors during the COVID-19 pandemic.

METHODS

The study involved 297 children, aged from 7.3 to 18.0 years, whose processors were upgraded to either Nucleus 7 or Kanso 2, or to Sonnet 2 or Rondo 3. To document the benefits of the upgrades, a speech-in-noise discrimination test and Patient Reported Outcome Measures (PROMs) were used.

RESULTS

There was a significant benefit from the newer processors in terms of speech discrimination in noise. Patient Reported Outcome Measures (PROMs) indicated less hearing disability, a higher level of functioning in everyday life situations, and more satisfaction with the new speech processor in social situations.

CONCLUSION

There is a measurable improvement in performance when the devices are upgraded to the new technology.