Amplification of the poorer ear by StereoBiCROS in case of asymmetric sensorineural hearing loss: effect on tinnitus.

Tinnitus is prevalent among patients suffering from Single-Sided Deafness (SSD) and Asymmetrical Hearing Loss (AHL). In addition to bothersome tinnitus in the poorer ear, these patients also report issues with understanding speech in noise and sound localization. The conventional treatment options offered to these patients to improve auditory abilities are cochlear implantation, bone conduction devices or Contralateral Routing Of Signal (CROS) hearing aids. It was recently found that the benefit of cochlear implantation for tinnitus associated with AHL/SSD was greater than the other two approaches. It is conceivable that the lack of stimulation provided to the poorer ear in these last approaches explains their modest impact on tinnitus perception. A new technology that combines the ability to reroute the sound from the poorer ear to the good ear (CROS system) while still stimulating the poorer ear with conventional sound amplification has recently been developed: the StereoBiCROS system. The aim of this study was to investigate the effects of this new device on tinnitus. Twelve AHL and two SSD patients aged 70.7 ± 7.9 years with tinnitus were fitted with bilateral hearing aids that included 3 programs: Stereophonic, BiCROS and StereoBiCROS (CROS + bilateral amplification). The short-and long-term effect of the approach on tinnitus was assessed using a tinnitus Loudness Visual Analog Scale (VAS) and the Tinnitus Handicap Inventory (THI), respectively. Both the VAS and the THI were used before and one month after the hearing aid fitting. Of the 14 patients who used their hearing aids daily (12.6 ± 1.6 h per day) the StereoBiCROS program was the most used program (81.8 ± 20.5% of the time). The average THI total score decreased from 47 (± 22) to 15 (± 16) (p = 0.002) and the VAS-Loudness score decreased from 7 (± 1) to 2 (± 2) (p < 0.001) after the one-month trial period. In conclusion, StereoBiCROS stimulation strategy seems to offer an effective alternative to reduce tinnitus handicap and loudness for patients with AHL/SSD and tinnitus. This effect may be driven by sound amplification of the poorer ear.

Electrical Field Interactions during Adjacent Electrode Stimulations: eABR Evaluation in Cochlear Implant Users.

The present study investigates how electrically evoked Auditory Brainstem Responses (eABRs) can be used to measure local channel interactions along cochlear implant (CI) electrode arrays. eABRs were recorded from 16 experienced CI patients in response to electrical pulse trains delivered using three stimulation configurations: (1) single electrode stimulations (E11 or E13); (2) simultaneous stimulation from two electrodes separated by one (En and En+2, E11 and E13); and (3) stimulations from three consecutive electrodes (E11, E12, and E13). Stimulation level was kept constant at 70% electrical dynamic range (EDR) on the two flanking electrodes (E11 and E13) and was varied from 0 to 100% EDR on the middle electrode (E12). We hypothesized that increasing the middle electrode stimulation level would cause increasing local electrical interactions, reflected in characteristics of the evoked compound eABR. Results show that group averaged eABR wave III and V latency and amplitude were reduced when stimulation level at the middle electrode was increased, in particular when stimulation level on E12 reached 40, 70, and 100% EDR. Compound eABRs can provide a detailed individual quantification of electrical interactions occurring at specific electrodes along the CI electrode array. This approach allows a fine determination of interactions at the single electrode level potentially informing audiological decisions regarding mapping of CI systems.

Evaluation of a New Bone Conduction Device for the Rehabilitation of Single-Sided Deafness: Effects on Speech Understanding in Noise.

INTRODUCTION: A new external, adhesive, no-pressure bone-conduction device provides rehabilitation for conductive hearing loss and single-sided deafness (SSD). The purpose of the study is to evaluate speech recognition performance with the bone-conduction contralateral routing of signal (aBC-CROS) and compare it to an air-conduction CROS (AC-CROS) used by subjects for at least 1 year. METHODS: Ten SSD patients underwent speech understanding in noise tests with their AC-CROS, the aBC-CROS, and unaided. The 1st test session took place the day the aBC-CROS was fitted, with the second session after 2 weeks of aBC-CROS use. Two configurations were used: speech presented on the deaf side and noise on the normal side and the reverse. RESULTS: The speech recognition threshold (SRT) improved with both devices when speech was presented to the deaf side. Nine patients showed significant improvement (p < 0.016) with the AC-CROS (mean: 2.8 dB) and the aBC-CROS (mean: 3.0 dB). Mean difference of improvement was significant between unaided and aBC-CROS (p = 0.001) or AC-CROS (p = 0.006). The SRT deteriorated by an average of 2.3 dB with the AC-CROS with noise presented on the deaf side, with significance found for six patients (p < 0.016). The aBC-CROS did not affect performance in this configuration (mean improvement: 0.3 dB) and only one patient had a significant SRT degradation (p < 0.016). Mean difference of improvement was significant between the AC-CROS and aBC-CROS (p = 0.021) or unaided (p = 0.05). DISCUSSION: The aBC-CROS is a good alternative to the existing CROS devices for SSD rehabilitation, as it offers the same benefit with none of the drawbacks when noise is on the patient's deaf side.

Intra-Cochlear Current Spread Correlates with Speech Perception in Experienced Adult Cochlear Implant Users.

Broader intra-cochlear current spread (ICCS) implies higher cochlear implant (CI) channel interactions. This study aimed to investigate the relationship between ICCS and speech intelligibility in experienced CI users. Using voltage matrices collected for impedance measurements, an individual exponential spread coefficient (ESC) was computed. Speech audiometry was performed to determine the intelligibility at 40 dB Sound Pressure Level (SPL) and the 50% speech reception threshold: I40 and SRT50 respectively. Correlations between ESC and either I40 or SRT50 were assessed. A total of 36 adults (mean age: 50 years) with more than 11 months (mean: 34 months) of CI experience were included. In the 21 subjects for whom all electrodes were active, ESC was moderately correlated with both I40 (r = -0.557, p = 0.009) and SRT50 (r = 0.569, p = 0.007). The results indicate that speech perception performance is negatively affected by the ICCS. Estimates of current spread at the closest vicinity of CI electrodes and prior to any activation of auditory neurons are indispensable to better characterize the relationship between CI stimulation and auditory perception in cochlear implantees.

Word Recognition and Frequency Selectivity in Cochlear Implant Simulation: Effect of Channel Interaction.

In cochlear implants (CI), spread of neural excitation may produce channel interaction. Channel interaction disturbs the spectral resolution and, among other factors, seems to impair speech recognition, especially in noise. In this study, two tests were performed with 20 adult normal-hearing (NH) subjects under different vocoded simulations. First, there was a measurement of word recognition in noise while varying the number of selected channels (4, 8, 12 or 16 maxima out of 20) and the degree of simulated channel interaction ("Low", "Medium" and "High"). Then, there was an evaluation of spectral resolution function of the degree of simulated channel interaction, reflected by the sharpness (Q10dB) of psychophysical tuning curves (PTCs). The results showed a significant effect of the simulated channel interaction on word recognition but did not find an effect of the number of selected channels. The intelligibility decreased significantly for the highest degree of channel interaction. Similarly, the highest simulated channel interaction impaired significantly the Q10dB. Additionally, a strong intra-individual correlation between frequency selectivity and word recognition in noise was observed. Lastly, the individual changes in frequency selectivity were positively correlated with the changes in word recognition when the degree of interaction went from "Low" to "High". To conclude, the degradation seen for the highest degree of channel interaction suggests a threshold effect on frequency selectivity and word recognition. The correlation between frequency selectivity and intelligibility in noise supports the hypothesis that PTCs Q10dB can account for word recognition in certain conditions. Moreover, the individual variations of performances observed among subjects suggest that channel interaction does not have the same effect on each individual. Finally, these results highlight the importance of taking into account subjects' individuality and to evaluate channel interaction through the speech processor.

Influence of microphone soiling on syllable recognition in cochlear implants: simulation and recognition in noise.

BACKGROUND: The microphone is the first link of the sound processing chain and if there is dirt on the membrane or in the input port, the frequency response is modified. OBJECTIVE: The effect of microphone cleaning in cochlear implants (CI) was studied by measuring speech perception scores in the noise of CI users and of normal hearing (NH) subjects with a CI simulator. MATERIAL AND METHODS: Sixty-one adult CI users and 20 NH were tested. In CI subjects, speech comprehension scores in noise were compared before and after cleaning microphone ports with one of two different cleaning procedures. NH listeners were tested using a vocoder that simulated soiled microphones. Two main coding schemes were considered, channel-picking (CP) and fixed-channel (FC). RESULTS: With NH subjects, the effect of the coding strategy and degree of soiling was statistically significant (p < 10-4); for the intermediate signal to noise ratios (SNRs), the recognition percentages were clearly affected. With CI users, cleaning the microphones significantly improved the recognition scores (p < 10-4). The two cleaning procedures considered turned out to be significantly different (p < 10-4). CONCLUSIONS: It is suggested to perform a regular microphone port cleaning to avoid deep soiling which leads to a decrease in speech understanding.

A New Speech, Spatial, and Qualities of Hearing Scale Short-Form: Factor, Cluster, and Comparative Analyses.

OBJECTIVES: The objective of this work was to build a 15-item short-form of the Speech Spatial and Qualities of Hearing Scale (SSQ) that maintains the three-factor structure of the full form, using a data-driven approach consistent with internationally recognized procedures for short-form building. This included the validation of the new short-form on an independent sample and an in-depth, comparative analysis of all existing, full and short SSQ forms. DESIGN: Data from a previous study involving 98 normal-hearing (NH) individuals and 196 people with hearing impairments (HI), non hearing aid wearers, along with results from several other published SSQ studies, were used for developing the short-form. Data from a new and independent sample of 35 NH and 88 HI hearing aid wearers were used to validate the new short-form. Factor and hierarchical cluster analyses were used to check the factor structure and internal consistency of the new short-form. In addition, the new short-form was compared with all other SSQ forms, including the full SSQ, the German SSQ15, the SSQ12, and the SSQ5. Construct validity was further assessed by testing statistical relationships between scores and audiometric factors, including pure-tone threshold averages (PTAs) and left/right PTA asymmetry. Receiver-operating characteristic analyses were used to compare the ability of different SSQ forms to discriminate between NH and HI (HI non hearing aid wearers and HI hearing aid wearers) individuals. RESULTS: Compared all other SSQ forms, including the full SSQ, the new short-form showed negligible cross-loading across the three main subscales and greater discriminatory power between NH and HI subjects (as indicated by a larger area under the receiver-operating characteristic curve), as well as between the main subscales (especially Speech and Qualities). Moreover, the new, 5-item Spatial subscale showed increased sensitivity to left/right PTA asymmetry. Very good internal consistency and homogeneity and high correlations with the SSQ were obtained for all short-forms. CONCLUSIONS: While maintaining the three-factor structure of the full SSQ, and exceeding the latter in terms of construct validity and sensitivity to audiometric variables, the new 15-item SSQ affords a substantial reduction in the number of items and, thus, in test time. Based on overall scores, Speech subscores, or Spatial subscores, but not Qualities subscores, the 15-item SSQ appears to be more sensitive to differences in self-evaluated hearing abilities between NH and HI subjects than the full SSQ.

A New Method for Assessing Masking and Residual Inhibition of Tinnitus.

Tinnitus masking and residual inhibition (RI) are two well-known psychoacoustic measures of tinnitus. While it has long been suggested that they may provide diagnostic and prognostic information, these measures are still rarely performed in clinics, as they are too time consuming. Given this issue, the main goal of the present study was to validate a new method for assessing these measures. An acoustic sequence made of pulsed stimuli, which included a fixed stimulus duration and interstimulus interval, was applied to 68 tinnitus patients at two testing sites. First, the minimum masking level (MML) was measured by raising the stimulus intensity until the tinnitus was unheard during the stimulus presentation. Second, the level of the stimulus was further increased until the tinnitus was suppressed during the silence interval between the acoustic pulses. This level was called the minimum residual inhibition level (MRIL). The sequential measurement of MML and MRIL from the same stimulus condition offers several advantages such as time efficiency and the ability to compare results between the MRIL and MML. Our study confirms that, from this new approach, MML and MRIL can be easily and quickly obtained from a wide variety of patients displaying either normal hearing or different hearing loss configurations. Indeed, MML was obtained in all patients except one (98.5%), and some level of MRIL was found on 59 patients (86.7%). More so, this approach allows the categorization of tinnitus patients into different subgroups based on the properties of their MRIL.

Superior Semicircular Canal Ampullae Dehiscence As Part of the Spectrum of the Third Window Abnormalities: A Case Study.

A 60-year-old man was referred to the ENT department for intense episodic vertigo triggered by loud sounds. Pure tone audiometry and otoneurological assessment, including videonystagmography using auditory stimulation and cervical vestibular evoked myogenic potential measures, conducted to the hypothesis of a third window syndrome in the left ear. Results from the high-resolution computed tomography of the petrous bone confirmed the hypothesis and revealed the presence of a submillimeter semicircular canal dehiscence, located between the left lateral and superior semicircular canal ampullae on the left side.

Binaural Diplacusis and Its Relationship with Hearing-Threshold Asymmetry.

Binaural pitch diplacusis refers to a perceptual anomaly whereby the same sound is perceived as having a different pitch depending on whether it is presented in the left or the right ear. Results in the literature suggest that this phenomenon is more prevalent, and larger, in individuals with asymmetric hearing loss than in individuals with symmetric hearing. However, because studies devoted to this effect have thus far involved small samples, the prevalence of the effect, and its relationship with interaural asymmetries in hearing thresholds, remain unclear. In this study, psychometric functions for interaural pitch comparisons were measured in 55 subjects, including 12 normal-hearing and 43 hearing-impaired participants. Statistically significant pitch differences between the left and right ears were observed in normal-hearing participants, but the effect was usually small (less than 1.5/16 octave, or about 7%). For the hearing-impaired participants, statistically significant interaural pitch differences were found in about three-quarters of the cases. Moreover, for about half of these participants, the difference exceeded 1.5/16 octaves and, in some participants, was as large as or larger than 1/4 octave. This was the case even for the lowest frequency tested, 500 Hz. The pitch differences were weakly, but significantly, correlated with the difference in hearing thresholds between the two ears, such that larger threshold asymmetries were statistically associated with larger pitch differences. For the vast majority of the hearing-impaired participants, the direction of the pitch differences was such that pitch was perceived as higher on the side with the higher (i.e., 'worse') hearing thresholds than on the opposite side. These findings are difficult to reconcile with purely temporal models of pitch perception, but may be accounted for by place-based or spectrotemporal models.

A Cochlear Implant Performance Prognostic Test Based on Electrical Field Interactions Evaluated by eABR (Electrical Auditory Brainstem Responses).

BACKGROUND: Cochlear implants (CIs) are neural prostheses that have been used routinely in the clinic over the past 25 years. They allow children who were born profoundly deaf, as well as adults affected by hearing loss for whom conventional hearing aids are insufficient, to attain a functional level of hearing. The "modern" CI (i.e., a multi-electrode implant using sequential coding strategies) has yielded good speech comprehension outcomes (recognition level for monosyllabic words about 50% to 60%, and sentence comprehension close to 90%). These good average results however hide a very important interindividual variability as scores in a given patients' population often vary from 5 to 95% in comparable testing conditions. Our aim was to develop a prognostic model for patients with unilateral CI. A novel method of objectively measuring electrical and neuronal interactions using electrical auditory brainstem responses (eABRs) is proposed. METHODS AND FINDINGS: The method consists of two measurements: 1) eABR measurements with stimulation by a single electrode at 70% of the dynamic range (four electrodes distributed within the cochlea were tested), followed by a summation of these four eABRs; 2) Measurement of a single eABR with stimulation from all four electrodes at 70% of the dynamic range. A comparison of the eABRs obtained by these two measurements, defined as the monaural interaction component (MIC), indicated electrical and neural interactions between the stimulation channels. Speech recognition performance without lip reading was measured for each patient using a logatome test (64 "vowel-consonant-vowel"; VCV; by forced choice of 1 out of 16). eABRs were measured in 16 CI patients (CIs with 20 electrodes, Digisonic SP; Oticon Medical ®, Vallauris, France). Significant correlations were found between speech recognition performance and the ratio of the amplitude of the V wave of the eABRs obtained with the two measurements (Pearson's linear regression model, parametric correlation: r2 = 0.26, p<0.05). CONCLUSIONS: This prognostic model allowed a substantial amount of the interindividual variance in speech recognition scores to be explained. The present study used measurements of electrical and neuronal interactions by eABR to assess patients' bio-electric capacity to use multiple information channels supplied by the implant. This type of prognostic information may be valuable in several ways. On the patient level, it allows customizing of individual treatments. ClinicalTrials.gov Identifier: NCT01805167.

Hearing rehabilitation with a binaural cochlear implant in a patient with Erdheim-Chester disease.

OBJECTIVE AND IMPORTANCE: Erdheim-Chester disease (ECD) is a rare non-Langerhans form of histiocytosis. This paper reports an exceptional case of bilateral neural involvement, responsible for profound hearing loss. Bilateral cochlear implantation was performed. CLINICAL PRESENTATION: We present a 57-year-old man affected by ECD with profound bilateral hearing loss. INTERVENTION: The patient underwent cochlear implantation with a binaural Digisonic(®) cochlear implant, 7 years after the initial diagnosis. RESULTS: Speech intelligibility rose to a plateau after about 6 months of cochlear implant use. The average outcome of speech intelligibility over time was 55% for dissyllabic words without lip reading, and 70% for sentences. Perception score decreased before the patient died from ECD. CONCLUSION: A description of the ECD and its otological manifestations is presented. This paper reports the effective hearing rehabilitation of profound bilateral hearing loss by the means of a binaural Digisonic(®) cochlear implant.

Factors affecting auditory performance of postlinguistically deaf adults using cochlear implants: an update with 2251 patients.

OBJECTIVE: To update a 15-year-old study of 800 postlinguistically deaf adult patients showing how duration of severe to profound hearing loss, age at cochlear implantation (CI), age at onset of severe to profound hearing loss, etiology and CI experience affected CI outcome. STUDY DESIGN: Retrospective multicenter study. METHODS: Data from 2251 adult patients implanted since 2003 in 15 international centers were collected and speech scores in quiet were converted to percentile ranks to remove differences between centers. RESULTS: The negative effect of long duration of severe to profound hearing loss was less important in the new data than in 1996; the effects of age at CI and age at onset of severe to profound hearing loss were delayed until older ages; etiology had a smaller effect, and the effect of CI experience was greater with a steeper learning curve. Patients with longer durations of severe to profound hearing loss were less likely to improve with CI experience than patients with shorter duration of severe to profound hearing loss. CONCLUSIONS: The factors that were relevant in 1996 were still relevant in 2011, although their relative importance had changed. Relaxed patient selection criteria, improved clinical management of hearing loss, modifications of surgical practice, and improved devices may explain the differences.

Benefits of the HiRes 120 coding strategy combined with the Harmony processor in an adult European multicentre study.

CONCLUSION: The Harmony processor was found to be reliable, comfortable and offered a substantially increased battery life compared with the previous generation processor. No significant improvement in speech understanding with HiRes was demonstrated from objective measures, but the majority of subjects showed a clear subjective preference for the combination HiRes 120/Harmony processor. OBJECTIVES: To evaluate experience with the Harmony™ sound processor, together with the HiRes 120 strategy. METHODS: Postlingually deafened adults implanted with a CII or HiRes 90K were included and divided into three groups: (1) experienced users using the Platinum body-worn processor; (2) experienced users who had been using other processors; (3) new users with the Harmony processor from first fitting. The latter group entered a randomized crossover protocol where half were initially fitted with HiRes and half with HiRes 120. The initial strategy was used for 3 months and the alternative for a further 3 months. Speech perception tests and questionnaires were performed. RESULTS: The study included 65 subjects. Implementing HiRes 120 was straightforward. The speech test group results did not show significant differences between HiRes and HiRes 120. However, the questionnaires showed significantly higher ratings for HiRes 120 in some instances. Subjects were highly satisfied with the Harmony processor.

A model-based analysis of the "combined-stimulation advantage".

Improvements in speech-recognition performance resulting from the addition of low-frequency information to electric (or vocoded) signals have attracted considerable interest in recent years. An important question is whether these improvements reflect a form of constructive perceptual interaction-whereby acoustic cues enhance the perception of electric or vocoded signals-or whether they can be explained without assuming any interaction. To address this question, speech-recognition performance was measured in 24 normal-hearing listeners using lowpass-filtered, vocoded, and "combined" (lowpass + vocoded) words presented either in quiet or in a realistic background (cafeteria noise), for different signal-to-noise ratios, different lowpass-filter cutoff frequencies, and different numbers of vocoder bands. The results of these measures were then compared to the predictions of three models of cue combination, including a "probability-summation" model and two Gaussian signal detection theory (SDT) models-one (the "independent-noises" model) involving pre-combination noises, and the other (the "late-noise" model) involving post-combination noise. Consistent with previous findings, speech-recognition performance with combined stimulation was significantly higher than performance with vocoded or lowpass stimuli alone, and it was also higher than predicted by the probability-summation model. The two Gaussian-SDT models could account quantitatively for the data. Moreover, a Bayesian model-comparison procedure demonstrated that, given the data, these two models were far more likely than the probability-summation model. Since these models do not involve any constructive-interaction mechanism, this demonstrates that constructive interactions are not needed to explain the combined-stimulation benefits measured in this study. It will be important for future studies to investigate whether this conclusion generalizes to other test conditions, including real EAS, and to further test the assumptions of these different models of the combined-stimulation advantage.

Laparoscopic implantation of neural electrodes on pelvic nerves: an experimental study on the obturator nerve in a chronic minipig model.

BACKGROUND: Laparoscopic exposure of pelvic nerves has opened a new area in the field of neuromodulation. However, electrode design and material deterioration remain issues that limit clinical application. The objective of this study was to evaluate experimentally the laparoscopic implantation of different types of neural electrodes in order to achieve functional and selective electrical stimulation of pelvic nerves. METHODS: This was a prospective comparative study of the laparoscopic implantation and tolerance and efficacy of three monopolar cuff electrodes implanted on the obturator nerve in ten Göttingen minipigs (18-20 months old; 14.5-24 kg body weight). Animals were allocated to two groups. A 3-mm-diameter laparoscopic instrument was used during dissection of paravesical fossa and obturator nerve on both sides in order to minimize nerve damage. In all animals, a "split-cylinder" cuff electrode was implanted around the left obturator nerve. On the right side, a "lasso" cuff electrode was implanted in the first group and a "closed-cylinder" cuff was implanted in the second group. Electrical stimulation (0-5 V, 20 Hz) was performed for implanted electrodes on days 0, 7, 15, 30, 45, 60, and 90. Current intensity thresholds were identified by palpation of muscle contraction. Strength developed according to stimulation level and was measured using weight transducers. RESULTS: All procedures were performed by laparoscopy. Mean operative times differed significantly among groups, the shortest being for split-cylinder electrodes (P = 0.0002). No electrical spread phenomena were observed. Initial thresholds were below 1.5 V (range = 0.5-1.3); however, a significant rise was observed, with time to a maximum of 2.7 V (P < 0.0001). Only split-cylinder electrodes remained functional after 3 months. The mean value of maximum strength remained stable during the study period (P = 0.21, NS). CONCLUSIONS: The laparoscopic approach to implanting neuroprostheses seems to be very attractive. Furthermore, this approach could allow highly selective nerve stimulation to be achieved using simpler devices such as split-cylinder monopolar electrodes.

Relationship between age of hearing-loss onset, hearing-loss duration, and speech recognition in individuals with severe-to-profound high-frequency hearing loss.

The factors responsible for interindividual differences in speech-understanding ability among hearing-impaired listeners are not well understood. Although audibility has been found to account for some of this variability, other factors may play a role. This study sought to examine whether part of the large interindividual variability of speech-recognition performance in individuals with severe-to-profound high-frequency hearing loss could be accounted for by differences in hearing-loss onset type (early, progressive, or sudden), age at hearing-loss onset, or hearing-loss duration. Other potential factors including age, hearing thresholds, speech-presentation levels, and speech audibility were controlled. Percent-correct (PC) scores for syllables in dissyllabic words, which were either unprocessed or lowpass filtered at cutoff frequencies ranging from 250 to 2,000 Hz, were measured in 20 subjects (40 ears) with severe-to-profound hearing losses above 1 kHz. For comparison purposes, 20 normal-hearing subjects (20 ears) were also tested using the same filtering conditions and a range of speech levels (10-80 dB SPL). Significantly higher asymptotic PCs were observed in the early (<=4 years) hearing-loss onset group than in both the progressive- and sudden-onset groups, even though the three groups did not differ significantly with respect to age, hearing thresholds, or speech audibility. In addition, significant negative correlations between PC and hearing-loss onset age, and positive correlations between PC and hearing-loss duration were observed. These variables accounted for a greater proportion of the variance in speech-intelligibility scores than, and were not significantly correlated with, speech audibility, as quantified using a variant of the articulation index. Although the lack of statistical independence between hearing-loss onset type, hearing-loss onset age, hearing-loss duration, and age complicate and limit the interpretation of the results, these findings indicate that other variables than audibility can influence speech intelligibility in listeners with severe-to-profound high-frequency hearing loss.