Considerable advancements in cochlear implant technology (e.g., electric acoustic stimulation) and assessment materials have yielded expanded criteria. Despite this, it is unclear whether individuals with better audiometric thresholds and speech understanding are being referred for cochlear implant workup and pursuing cochlear implantation. The purpose of this study was to characterize the mean auditory and demographic profile of adults presenting for preoperative cochlear implant workup. Data were collected prospectively for all adult preoperative workups at Vanderbilt from 2013 to 2015. Subjects included 287 adults (253 postlingually deafened) with a mean age of 62.3 years. Each individual was assessed using the minimum speech test battery, spectral modulation detection, subjective questionnaires, and cognitive screening. Mean consonant-nucleus-consonant word scores, AzBio sentence scores, and pure-tone averages for postlingually deafened adults were 10%, 13%, and 89 dB HL, respectively, for the ear to be implanted. Seventy-three individuals (25.4%) met labeled indications for Hybrid-L and 207 individuals (72.1%) had aidable hearing in the better hearing ear to be used in a bimodal hearing configuration. These results suggest that mean speech understanding evaluated at cochlear implant workup remains very low despite recent advancements. Greater awareness and insurance accessibility may be needed to make cochlear implant technology available to those who qualify for electric acoustic stimulation devices as well as individuals meeting conventional cochlear implant criteria.

Objective To describe the incidence, clinical presentation, and performance of cochlear implant (CI) recipients with tip fold-over. Study design Retrospective case series. Setting Tertiary referral center. Patients CI recipients who underwent postoperative CT scanning. Intervention(s) Tip fold-over was identified tomographically using previously-validated software that identifies the electrode array. Electrophysiologic testing including spread of excitation (SOE) or electric field imaging (EFI) was measured on those with fold-over. Main outcome measure(s) Location of the fold-over; audiological performance pre and post selective deactivation of fold-over electrodes. Results 303 ears of 235 CI recipients had postoperative CTs available for review. Six (1.98%) had tip fold-over with 5/6 right-sided ears. Tip fold-over occurred predominantly at 270° and was associated with pre-curved electrodes (5/6). Patients did not report audiological complaints during initial activation. In one patient, the electrode array remained within the scala tympani with preserved residual hearing despite the fold-over. SOE supported tip fold-over, but the predictive value was not clear. EFI predicted location of the fold-over with clear predictive value in one patient. At an average follow-up of 11 months, three subjects underwent deactivation of the overlapping electrodes with two of them showing marked audiological improvement. Conclusions In a large academic center with experienced surgeons, tip fold-over occurred at a rate of 1.98% but was not immediately identifiable clinically. CT imaging definitively showed tip fold-over. Deactivating involved electrodes may improve performance possibly avoiding revision surgery. EFI may be highly predictive of tip fold-over and can be run intraoperatively, potentially obviating the need for intra-op fluoroscopy.

Non-traditional pediatric implant recipients derive significant benefit from cochlear implantation. A large-scale reassessment of pediatric cochlear implant candidacy, including less severe hearing losses and higher preoperative speech recognition, is warranted to allow more children access to the benefits of cochlear implantation.

Objective The primary objective of this study was to assess the effect of electric and acoustic overlap for speech understanding in typical listening conditions using semi-diffuse noise. Design This study used a within-subjects, repeated-measures design including 11 experienced adult implant recipients (13 ears) with functional residual hearing in the implanted and non-implanted ear. The aided acoustic bandwidth was fixed and the low-frequency cutoff for the cochlear implant was varied systematically. Assessments were completed in the R-SPACE™ sound-simulation system which includes a semi-diffuse restaurant noise originating from eight loudspeakers placed circumferentially about the subject’s head. AzBio sentences were presented at 67 dBA with signal-to-noise ratio (SNR) varying between +10 and 0 dB determined individually to yield approximately 50–60% correct for the cochlear implant (CI) alone condition with full CI bandwidth. Listening conditions for all subjects included CI alone, bimodal (CI + contralateral hearing aid, HA), and bilateral-aided electric and acoustic stimulation (EAS; CI + bilateral HA). Low-frequency cutoffs both below and above the original “clinical software recommendation” frequency were tested for all patients, in all conditions. Subjects estimated listening difficulty for all conditions using listener ratings based on a visual analog scale. Results Three primary findings were that 1) there was statistically significant benefit of preserved acoustic hearing in the implanted ear for most overlap conditions, 2) the default clinical software recommendation rarely yielded the highest level of speech recognition (1 out of 13 ears), and 3) greater EAS overlap than that provided by the clinical recommendation yielded significant improvements in speech understanding. Conclusions For standard-electrode CI recipients with preserved hearing, spectral overlap of acoustic and electric stimuli yielded significantly better speech understanding and less listening effort in a laboratory-based, restaurant-noise simulation. In conclusion, EAS patients may derive more benefit from greater acoustic and electric overlap than given in current software fitting recommendations which are based solely on audiometric threshold. These data have larger scientific implications, as previous studies may not have assessed outcomes with optimized EAS parameters, thereby underestimating the benefit afforded by hearing preservation.

Adult cochlear implant (CI) recipients demonstrate a reliable relationship between spectral modulation detection and speech understanding. Prior studies documenting this relationship have focused on postlingually deafened adult CI recipients—leaving an open question regarding the relationship between spectral resolution and speech understanding for adults and children with prelingual onset of deafness. Here, we report CI performance on the measures of speech recognition and spectral modulation detection for 578 CI recipients including 477 postlingual adults, 65 prelingual adults, and 36 prelingual pediatric CI users. The results demonstrated a significant correlation between spectral modulation detection and various measures of speech understanding for 542 adult CI recipients. For 36 pediatric CI recipients, however, there was no significant correlation between spectral modulation detection and speech understanding in quiet or in noise nor was spectral modulation detection significantly correlated with listener age or age at implantation. These findings suggest that pediatric CI recipients might not depend upon spectral resolution for speech understanding in the same manner as adult CI recipients. It is possible that pediatric CI users are making use of different cues, such as those contained within the temporal envelope, to achieve high levels of speech understanding. Further investigation is warranted to investigate the relationship between spectral and temporal resolution and speech recognition to describe the underlying mechanisms driving peripheral auditory processing in pediatric CI users.