Speech Comprehension by Cochlear Implant Users Assessed with Evoked Potentials and Response Times.

INTRODUCTION: Cochlear implant (CI) users differ greatly in their rehabilitation outcomes, including speech understanding in noise. This variability may be related to brain changes associated with intact senses recruiting cortical areas from stimulation-deprived senses. Numerous studies have demonstrated such cross-modal reorganization in individuals with untreated hearing loss. How it is affected by regular use of hearing devices remains unclear, however. To shed light on this, the current study measured cortical responses reflecting comprehension abilities in experienced CI users and normal-hearing controls. METHODS: Using multichannel electroencephalography, we tested CI users who had used their devices for at least 12 months and closely matched controls (N = 2 × 13). Cortical responses reflecting comprehension abilities - the N400 and late positive complex (LPC) components - were evoked using congruent and incongruent digit-triplet stimuli. The participants' task was to assess digit-triplet congruency by means of timed button presses. All measurements were performed in speech-shaped noise 15 dB above individually measured speech recognition thresholds. Three stimulus presentation modes were used: auditory-only, visual-only, and visual-then-auditory. RESULTS: The analyses revealed no group differences in the N400 and LPC responses. In terms of response times, the CI users were slower and differentially affected by the three stimulus presentation modes relative to the controls. CONCLUSION: Compared to normal-hearing controls, experienced CI users may need more time to comprehend speech in noise. Response times can serve as a proxy for speech comprehension by CI users.

Amplitude Compression for Preventing Rollover at Above-Conversational Speech Levels.

Hearing aids provide nonlinear amplification to improve speech audibility and loudness perception. While more audibility typically increases speech intelligibility at low levels, the same is not true for above-conversational levels, where decreases in intelligibility ("rollover") can occur. In a previous study, we found rollover in speech intelligibility measurements made in quiet for 35 out of 74 test ears with a hearing loss. Furthermore, we found rollover occurrence in quiet to be associated with poorer speech intelligibility in noise as measured with linear amplification. Here, we retested 16 participants with rollover with three amplitude-compression settings. Two were designed to prevent rollover by applying slow- or fast-acting compression with a 5:1 compression ratio around the "sweet spot," that is, the area in an individual performance-intensity function with high intelligibility and listening comfort. The third, reference setting used gains and compression ratios prescribed by the "National Acoustic Laboratories Non-Linear 1" rule. Speech intelligibility was assessed in quiet and in noise. Pairwise preference judgments were also collected. For speech levels of 70 dB SPL and above, slow-acting sweet-spot compression gave better intelligibility in quiet and noise than the reference setting. Additionally, the participants clearly preferred slow-acting sweet-spot compression over the other settings. At lower levels, the three settings gave comparable speech intelligibility, and the participants preferred the reference setting over both sweet-spot settings. Overall, these results suggest that, for listeners with rollover, slow-acting sweet-spot compression is beneficial at 70 dB SPL and above, while at lower levels clinically established gain targets are more suited.

Value Propositions of Public Adult Hearing Rehabilitation in Denmark.

Objective: To obtain and evaluate detailed descriptions of potential value propositions as seen by adults undergoing hearing rehabilitation with hearing aids. Design: Semi-structured interviews with patients and audiologists, a literature search, and the inclusion of domain knowledge from experts and scientists were used to derive value propositions. A two-alternative forced-choice paradigm and probabilistic choice models were used to investigate hearing aid users' preferences for the value propositions through an online platform. Study sample: Twelve hearing aid users (mean age 70, range 59-70) and eleven clinicians were interviewed. A total of 173 experienced hearing aid users evaluated the value propositions. Results: Twenty-nine value propositions as described by patients, clinicians, and hearing care experts where identified, from which twenty-one value propositions were evaluated. Results of the pair-wise evaluation method show that the value propositions judged to be the most important for the hearing aid users were: "13. To solve the hearing problem you have", "09. Thorough diagnosis of the hearing", and "16. The hearing aid solution is adapted to individual needs", which are related to finding the correct hearing solution and to be considered in the process. The value propositions judged to be least important were: "04 Next of kin and others involved in the process", "26. To be in the same room as the practitioner", and "29. The practitioner's human characteristics", related to the involvement of others in the process and the proximity and personal manner of the practitioners.

Revisiting Auditory Profiling: Can Cognitive Factors Improve the Prediction of Aided Speech-in-Noise Outcome?

Hearing aids (HA) are the most common type of rehabilitation treatment for age-related hearing loss. However, HA users often obtain limited benefit from their devices, particularly in noisy environments, and thus many HA candidates do not use them at all. A possible reason for this could be that current HA fittings are audiogram-based, that is, they neglect supra-threshold factors. In an earlier study, an auditory-profiling method was proposed as a basis for more personalized HA fittings. This method classifies HA users into four profiles that differ in terms of hearing sensitivity and supra-threshold hearing abilities. Previously, HA users belonging to these profiles showed significant differences in terms of speech recognition in noise but not subjective assessments of speech-in-noise (SIN) outcome. Moreover, large individual differences within some profiles were observed. The current study therefore explored if cognitive factors can help explain these differences and improve aided outcome prediction. Thirty-nine older HA users completed sets of auditory and SIN tests as well as two tablet-based cognitive measures (the Corsi block-tapping and trail-making tests). Principal component analyses were applied to extract the dominant sources of variance both within individual tests producing many variables and within the three types of tests. Multiple linear regression analyses performed on the extracted components showed that auditory factors were related to aided speech recognition in noise but not to subjective SIN outcome. Cognitive factors were unrelated to aided SIN outcome. Overall, these findings provide limited support for adding those two cognitive tests to the profiling of HA users.

Veterinarians' role in clients' decision-making regarding seriously ill companion animal patients.

BACKGROUND: When companion animals become seriously ill clients may have doubts about treatment choices, if any, and turn to veterinarians for help. But how should veterinarians reply? Influence on clients' decision-making may or may not be acceptable-depending on one's attitude to principles such as 'paternalism', 'respect for autonomy' and 'shared decision-making'. This study takes as a starting point a situation where the animal is chronically ill, or aged, with potentially reduced animal welfare and client quality of life, and thus where clients need to consider treatment options or euthanasia. It is assumed throughout that both veterinarians and clients have the animals' best interest at heart. The purpose of the study was to explore the challenges these situations hold and to investigate how clients experience veterinary influence. A second aim was to reflect on the ethical implications of the role of veterinarians in these situations. Qualitative interviews were conducted with 12 dog owners considering treatment or euthanasia of their chronically ill or aged dogs. RESULTS: Challenges relating to the dog and to the client were identified. Some situations left the interviewees hesitant, e.g. if lacking a clear cut-off point, the dog appeared normal, the interviewee felt uncertain about treatments or animal welfare, or experienced conflicting concerns. Some interviewees found that veterinarians could influence their decisions. Such influence was received in different ways by the interviewees. Some interviewees wanted active involvement of the veterinarian in the decision-making process, and this may challenge a veterinarian's wish to respect client autonomy. CONCLUSIONS: Different preferences are likely to exist amongst both veterinarians and clients about veterinary involvement in clients' decision-making, and such preferences may vary according to the situation. It is suggested, that one way to handle this challenge is to include respect for client preference on veterinary involvement under a wider understanding of respect for autonomy, and to apply models of shared decision-making to veterinary practice. In any case there is a need to further explore the challenges these situations raise, and for the veterinary profession to engage in more formal and structured deliberation over the role of veterinarians in relation to clients' decision-making.