Perceptual organization of sequential stimuli in cochlear implant listeners: A temporal processing approach.

OBJECTIVE: Cochlear Implant (CI) users often suffer difficulties in perceiving speech in noisy environments that could be attributed to reduced Auditory Stream Segregation (ASS) ability. ASS is the process used to separate a complex sound into different perceptual streams. The evidence that CI listeners routinely experience stream segregation skill is limited and equivocal. The present study was aimed to investigate the effects of temporal cues on ASS performance in postlingually deaf listeners with CI. METHODS: Nineteen (age range: 28-64 years old) monaurally cochlear implanted listener participated in this study. They were presented with 30-s sequences of alternating stimuli in a repeating A-B-A-A-B-A…sequence, where "tone A" corresponds to a stimulus applied to electrode 11, and "tone B" to a stimulus on one of the other electrode. To investigate the effect of temporal cues on ASS, four different tone repetition times (TRTs) were utilized: 50, 100, 150, and 200 ms. Speech discrimination scores in noise were also recorded for every CI recipients. RESULTS: Only 6 (32%) CI users demonstrated ASS pattern similar to the normal hearing subjects, while the majority of the users (n=13) possessed poorer ASS skills. An analysis of variance showed a significant effect of electrode separation (p<0.001) and TRT (p=0.041), but there was no significant interaction between electrode separation and TRT variables. The best ASS performance was obtained when TRT was 200 ms, and there was no significant effect for other TRT conditions. Moderate, significant correlations between streaming and speech discrimination measurement in noise was also observed (r=0.62), with better stream segregation associated with better understanding of speech in noise. CONCLUSION: ASS is a contributing factor in the ability to perceive speech in background noise. The inability of some CI recipients to perform stream segregation may therefore contribute to their difficulties in noisy backgrounds. Furthermore, stream segregation ability is related to the tone repetition time between the sounds.

Don't look at it as a miracle cure: Contested notions of success and failure in family narratives of pediatric cochlear implantation.

Cochlear implants (CIs) are a routine treatment for children identified with a qualifying hearing loss. The CI, however, must be accompanied by a long-term and intense auditory training regimen in order to possibly acquire spoken language with the device. This research investigates families' experiences when they opted for the CI and undertook the task of auditory training, but the child failed to achieve what might be clinically considered "success" - the ability to function solely using spoken language. Using a science and technology studies informed approach that places the CI within a complex sociotechnical system, this research shows the uncertain trajectory of the CI, as well as the contingency of the very notions of success and failure. To do so, data from in-depth interviews with a diverse sample of parents (n = 11) were collected. Results show the shifting definitions of failure and success within families, as well as suggest areas for further exploration regarding clinical practice and pediatric CIs. First, professionals' messaging often conveyed to parents a belief in the infallibility of the CI, this potentially caused "soft failure" to go undetected and unmitigated. Second, speech assessments used in clinical measurements of outcomes did not capture a holistic understanding of a child's identity and social integration, leaving out an important component for consideration of what a 'good outcome' is. Third, minority parents experience structural racism and clinical attitudes that may render "failure" more likely to be identified and expected in these children, an individualizing process that allows structural failures to go uncritiqued.

Partial deafness treatment.

The authors present the accepted strategy of Partial Deafness Treatment (PDT) based on long-term observation and results: 8-years long in adult patients and over 5-years long in children. In therapy, there are two fundamental modes of complementary stimulation in cases of moderate to severe hearing loss. One of them is the acoustic stimulation (AS), comprising patients who use amplification with hearing aid (HA) and/or middle ear implant (MEI). The other mode, presented by the authors in this study, is the electric stimulation using cochlear implant (PDCI). The entire material in this mode is divided into three groups: 1. Electrical Complement (EC); 2. Electric Acoustic Stimulation (EAS); and 3. Electric Stimulation (ES). Surgical approach in PDT is based on the 6-steps method, emphasizing round window approach to the scala tympani. The results obtained in the long-term follow-up shows the preservation of preoperative hearing in 97% of subjects. Overall, for all audiometric frequencies the differences in mean pre- and mean postoperative thresholds, measured before surgery and 3 months afterwards were not statistically significant (p>0.05). In all four groups we observed a significant increase in scores between pre-operative and 12 months after surgery both under quiet and noisy conditions. The presented concept, supported by the substantial material and long-term follow-up, allows the comprehensive approach to the treatment of partial deafness using different modes of stimulation.

Trends in cochlear implants.

More than 60,000 people worldwide use cochlear implants as a means to restore functional hearing. Although individual performance variability is still high, an average implant user can talk on the phone in a quiet environment. Cochlear-implant research has also matured as a field, as evidenced by the exponential growth in both the patient population and scientific publication. The present report examines current issues related to audiologic, clinical, engineering, anatomic, and physiologic aspects of cochlear implants, focusing on their psychophysical, speech, music, and cognitive performance. This report also forecasts clinical and research trends related to presurgical evaluation, fitting protocols, signal processing, and postsurgical rehabilitation in cochlear implants. Finally, a future landscape in amplification is presented that requires a unique, yet complementary, contribution from hearing aids, middle ear implants, and cochlear implants to achieve a total solution to the entire spectrum of hearing loss treatment and management.