Cochlear implant referral patterns in the UK suggest a postcode lottery with inequitable access for older adults; results of a pilot audit in five Audiology sites.

OBJECTIVE: To use a standardised reporting tool to identify potential eligible candidates for cochlear implant (CI) referral and quantify the proportion of adults who had a CI referral discussion after presenting with an audiogram within United Kingdom (UK) audiometric criteria. DESIGN: Retrospective multicentre 6-month audit of Audiology clinic databases. STUDY SAMPLE: A total of 810 adults from five geographically diverse UK Audiology sites. RESULTS: Data were collected in late 2019 after UK CI audiometric candidacy criteria changed; one site collected only 3 months of data. The proportion of potential eligible adults (based only on audiometry) considered for CI referral was 64% (521 out of 810) and varied by site (from 50% to 83%). About 24% of patients (123 out of 521) declined CI referral; this also varied across sites (12-45%). The median age of patients where CI referral was not considered was 80 years - significantly higher than the group where CI referral was considered (73 years). CONCLUSIONS: CI referral is dependent on where adults live, and how old they are. Older adults are significantly less likely to be considered for CI referral by Audiologists. Audiology clinics need more support to empower staff to talk to patients about CI referral.

Is non-linear frequency compression amplification beneficial to adults and children with hearing loss? A systematic review.

OBJECTIVE: To conduct a systematic review of the benefits of non-linear frequency compression (NLFC) in adults and children. DESIGN: Ten databases were searched for studies comparing the effects of NLFC and conventional processing (CP) for the period January 2008 to September 2017. STUDY SAMPLE: Twelve articles were included in this review: four adults and school-aged only, one pre-school only and three with both adults and school-aged children. RESULTS: A two-stage process was implemented to grade the evidence. The individual studies were graded based on their study type (from 1 = highest quality of evidence to 5 = the lowest quality) and then sub-graded based on their quality ("a" for "good quality" or "b" for "lesser quality"). All studies were awarded 4a, except the single pre-school study, which was awarded 2a. The overall evidence for each population was graded based on the quality, quantity and consistency of the studies. The body of evidence was rated as very low for both adults and school-aged children, but high for pre-school children. CONCLUSION: The low number (and quality) of studies means that evidence supporting the benefit from NLFC is inconclusive. Further high-quality RCTs are required to provide a conclusive answer to this question.

Adaptation to nonlinear frequency compression in normal-hearing adults: a comparison of training approaches.

OBJECTIVE: To identify which training approach, if any, is most effective for improving perception of frequency-compressed speech. DESIGN: A between-subject design using repeated measures. STUDY SAMPLE: Forty young adults with normal hearing were randomly allocated to one of four groups: a training group (sentence or consonant) or a control group (passive exposure or test-only). Test and training material differed in terms of material and speaker. RESULTS: On average, sentence training and passive exposure led to significantly improved sentence recognition (11.0% and 11.7%, respectively) compared with the consonant training group (2.5%) and test-only group (0.4%), whilst, consonant training led to significantly improved consonant recognition (8.8%) compared with the sentence training group (1.9%), passive exposure group (2.8%), and test-only group (0.8%). CONCLUSIONS: Sentence training led to improved sentence recognition, whilst consonant training led to improved consonant recognition. This suggests learning transferred between speakers and material but not stimuli. Passive exposure to sentence material led to an improvement in sentence recognition that was equivalent to gains from active training. This suggests that it may be possible to adapt passively to frequency-compressed speech.

Benefit from non-linear frequency compression hearing aids in a clinical setting: the effects of duration of experience and severity of high-frequency hearing loss.

OBJECTIVES: To determine whether non-linear frequency compression (NLFC) is effective for hearing-impaired adults in a clinical setting. To determine whether benefit from NLFC is related to duration of NLFC experience or severity of high-frequency hearing loss. DESIGN: Participants were fitted with Phonak frequency compression hearing aids as part of their standard clinical care, using the manufacturer's default fitting settings. Participants had been using NLFC for between 1 and 121 weeks at the time of testing. Speech recognition thresholds in noise and consonant recognition in quiet were measured with and without NLFC enabled. STUDY SAMPLE: Forty-six experienced adult hearing-aid users. RESULTS: Consonant recognition in quiet, but not speech recognition in noise was significantly better with NLFC enabled. There was no significant correlation between duration of frequency compression experience and benefit. Benefit for consonant recognition was negatively correlated with mean audiometric thresholds from 2-6 kHz. CONCLUSIONS: NLFC was beneficial for consonant recognition but not speech recognition in noise. There was no evidence to support the idea that a long period of acclimatization is necessary to gain full benefit. The relation between benefit and high-frequency thresholds might be explained by the poor audibility of compressed information for some listeners with severe loss.