Assessment of Binaural Benefits in Hearing and Hearing-Impaired Listeners.

PURPOSE: The purpose of this study was to (a) investigate which speech material is most appropriate as stimulus in head shadow effect (HSE) and binaural squelch (SQ) tests, (b) obtain normative values of both tests using the material decided to be optimal, and (c) explore the results in bilateral cochlear implant (CI) users. METHOD: Study participants consisted of 30 normal-hearing (NH) persons and 34 bilateral CI users. This study consisted of three phases. In the first phase, three different speech materials (1) monosyllabic words, (2) spondee words, and (3) sentences were compared in terms of (a) effect size, (b) test-retest reliability, and (c) interindividual variability. In the second phase, the speech material selected in the first phase was used to test a further 24 NHs to obtain normative values for both tests. In the third phase, tests were administered to a further 23 bilateral CI users, together with localization test and the Speech, Spatial, and Qualities of Hearing scale. RESULTS: The results of the first phase indicated that spondees and sentences were more robust materials compared with monosyllables. Although the effect size and interindividual variability were comparable for spondees and sentences, sentences had higher test-retest reliability in this sample of CI users. With sentences, the mean (± standard deviation) HSE and SQ in the NH group were 58 ± 14% and 22 ± 11%, respectively. In the CI group, the mean HSE and SQ were 49 ± 13% and 13 ± 14%, respectively. There were no statistically significant correlations between the test results and the interval between the implantations, the length of binaural listening experience, or the asymmetry between the ears. CONCLUSIONS: Sentences are preferred as stimulus material in the binaural HSE and SQ tests. Normative data are given for HSE and SQ with the LiCoS (linguistically controlled sentences) test. HSE is present for all bilateral CI users, whereas SQ is present in approximately seven out of 10 cases.

Effect of a CI Programming Fitting Tool with Artificial Intelligence in Experienced Cochlear Implant Patients.

OBJECTIVE: Cochlear implants (CIs) are the treatment of choice for patients with severe to profound hearing loss. The hearing results, however, considerably vary across patients. This may partly be due to variability in the CI fitting. We investigated the effect of FOX, a software tool to program CIs using artificial intelligence (AI), on hearing outcomes. METHODS: Forty-seven experienced CI patients who came to our tertiary CI center for their annual follow-up between 2017 and 2020 were recruited for this study. They received a new CI map created by the AI software tool. CI parameters and auditory outcomes obtained with this new map were compared with those of the initial manual map after 15 days of take-home experience. Within-patient differences were assessed. At the end of the study, the patients were offered a choice to continue using the AI map or to revert to their old manual map. RESULTS: Several auditory outcomes improved with the AI map, namely, pure tone audiometric threshold at 6,000 Hz (median improvement 10 dB, range = -20 to 50 dB, Z = -2.608, p = 0.008), phonemic discrimination scores (median improvement 10%, range = 0% to 30%, Z = -4.061, p = 0.001), and soft-intensity (median improvement of 10%, range = -20% to 90%, Z = -4.412, p < 0.001) to normal-intensity (median improvement of 10%, range = -30% to 60%, Z = -3.35, p < 0.001) speech audiometric scores. CONCLUSION: The AI-assisted CI mapping model as a potential assistive tool may improve audiological outcomes for experienced CI patients, including high-frequency pure tone audiometry and audiometric speech scores at low and normal presentation levels.Clinical trial registration: NCT03700268.

Prospective Comparison Between Manual and Computer-Assisted (FOX) Cochlear Implant Fitting in Newly Implanted Patients.

OBJECTIVE: A prospective, longitudinal, randomized controlled trial with an original crossover design for 1 year was conducted to compare manual fitting to artificial intelligence-based fitting in newly implanted patients. DESIGN: Twenty-four patients who received their first cochlear implant (CI) were randomly assigned to the manual or Fitting to Outcome eXpert (FOX) arm; they followed the corresponding fitting procedures for 1 year. After 1 year, each patient was switched to another arm. The number of fittings, auditory outcomes (pure-tone thresholds, loudness scaling curves, spectral discrimination scores, bisyllabic word recognition in quiet and noise, and speech tracking), fitting session questionnaire, and CI parameters (T level, C level, Threshold Sound Pressure Level (T-SPL), Comfortable Sound Pressure Level (C-SPL), and loudness growth value) were compared between the two groups. Differences between the two groups were analyzed using the Mann-Whitney test, and Holm corrections were applied for multiple statistical tests. At the end of the crossover session, patients were offered the choice to continue with their old or new map. RESULTS: As early as 3 mo postactivation, the FOX group showed less variability and significantly better speech intelligibility in quiet conditions at 40 and 55 dB SPL and noise ( p < 0.05) with median phoneme scores of 50%, 70%, and 50% at 55, 70, and 85 dB SPL compared with 45%, 50%, and 40%, respectively. This group showed better results at 12 mo postactivation ( p < 0.05). In the manual group, 100% of the patients decided to keep the new FOX map, and 82% performed better with the FOX map. In the FOX group, 63% of the patients decided to keep the manual map, although the measurable outcome had not improved. In this group, participants reported to prefer the manual map because it felt more comfortable, even if the FOX map gave better measured outcome. CONCLUSION: Although the study size remains relatively small, the AI-FOX approach was equivalent to or even outperformed the manual approach in hearing performance, comfort, and resources. Furthermore, FOX is a tool capable of continuous improvement by comparing its predictions with observed results and is continuously learning from clinicians' practice, which is why this technology promises major advances in the future.

Speech Audiometrical Results Before and After Reimplantation of Cochlear Implants.

OBJECTIVES: This study aimed to compare the audiological outcomes of cochlear reimplantation with those of the first cochlear implant (CI). DESIGN: A retrospective analysis was performed on the data of all CI recipients who received the first CI at the age of 8 years or above and who were subsequently reimplanted on the same side. All participants who received their first implant after January 1, 2000, and who were reimplanted before January 1, 2021, were included. CI recipients who were unable to perform an open-set of Flemish monosyllable speech audiometry were excluded. The participants' clinical files were reviewed in terms of the cause of hearing loss, age at the first and second implantation, device types, the time between the first and second surgery, speech reception scores before and after reimplantation, and the reason for reimplantation. RESULTS: Reimplantation was due to device failure in 19 out of 22 patients, performance decrement in two patients, and medical reasons in one patient. The interval between the first and second CI ranged from 8 to 218 mo. Within-subject analysis showed the speech reception performance with the second CI to be significantly better than that with the first CI at all follow-up time points, with average within-patient gains of 17%, 16%, 12%, and 15% at 3 mo, 9 mo, 3 years, and the highest scores achieved, respectively. After reimplantation, the performance was better than the last results before reimplantation, and this was significant from 9 mo after reimplantation onwards. Three patients (14%) had a performance degradation with the second CI, which was probably owing to (1) difficulties in reimplantation surgery leading to a reduced number of active channels, (2) insufficient experience with the second CI as the reimplantation has been performed recently, and (3) advanced fenestral and retrofenestral otosclerosis. CONCLUSIONS: The present study shows that speech reception performance after reimplantation yields faster and better results than the first implant. It takes a couple of months to get better results than those before the reimplantation. Only in a minority of participants, a small deterioration may be observed. It seems that soft failures in the absence of measurable technical abnormalities call for caution with regard to reimplantation.

Computational Audiology: New Approaches to Advance Hearing Health Care in the Digital Age.

The global digital transformation enables computational audiology for advanced clinical applications that can reduce the global burden of hearing loss. In this article, we describe emerging hearing-related artificial intelligence applications and argue for their potential to improve access, precision, and efficiency of hearing health care services. Also, we raise awareness of risks that must be addressed to enable a safe digital transformation in audiology. We envision a future where computational audiology is implemented via interoperable systems using shared data and where health care providers adopt expanded roles within a network of distributed expertise. This effort should take place in a health care system where privacy, responsibility of each stakeholder, and patients' safety and autonomy are all guarded by design.

Variability of fitting parameters across cochlear implant centres.

OBJECTIVE: As a follow-up to the studies by Vaerenberg et al. (Sci World J 501738:1-12, 2014) and Browning et al. (Cochlear Implant Int 21(3):1-13, 2020), who used questionnaires, we determined whether there are between-centre variations in the fitting of cochlear implants by analysing the methodology, fitting parameters and hearing results of patients from four centres with real data. The purpose of this study is to highlight the lack of streamlined mapping guides and outcome measures with respect to cochlear implant (CI) fittings. METHODS: A retrospective study with ninety-seven post-lingual adults with a nucleus cochlear implant placed between 2003 and 2013 was included to ensure at least 5 years of follow-up. The studied data were as follows: the methodology, including the fitter's professional background, the method of activation, the sequence of fitting sessions, the objectives measures and hearing outcomes; and the fitting parameters, including the speech processors, programming strategy, stimulation mode, T and C levels, T-SPL and C-SPL, maxima, pulse width, loudness growth and hearing results. RESULTS: This investigation highlights some common practices across professionals and CI centres: the activation of a CI is behavioural; impedances are systematically measured at each fitting; and some parameters are rarely modified. However, there are also differences, either between centres, such as the sequences of fitting sessions (p < 0.05) or their approach to spectral bands (p < 0.05), or even within centres, such as the policy regarding T and C levels at high frequencies compared to those at low and mid-frequencies. CONCLUSION: There are important variations between and within centres that reflect a lack of CI-related policies and outcome measures in the fitting of CI. CLINICAL TRIALS REGISTRY: NCT03700268.

A New Pathogenic Variant in the TRIOBP Associated with Profound Deafness Is Remediable with Cochlear Implantation.

BACKGROUND AND OBJECTIVES: A rare type of nonsyndromic autosomal recessive hereditary hearing loss is caused by pathogenic mutations in the TRIOBP gene mostly involving exons 6 and 7. These mutations cause hearing loss originating from dysfunction of sensory inner ear hair cells. Of all the affected siblings, 2 brothers and 1 sister, part of an Afghan family, were referred to our clinic for diagnostic workup and candidacy selection for cochlear implantation (CI). METHODS: Molecular analysis showed a homozygous c.1342C > T p. (Arg448*) pathogenic variant in exon 7 of the TRIOBP gene (reference sequence NM_001039141.2) in all 3 affected siblings. Clinical audiometry demonstrated profound sensorineural hearing loss in all 3 affected siblings (2 males and 1 female), and they were implanted unilaterally. RESULTS: One month after activation, the pure-tone averages with the CI processor were between 30 and 23 dBHL. Ten months after the first activation of the implant, open-set speech audiometry test could be performed for the first time in the 2 younger CI recipients (S5 and S9), and they could identify up to a maximum 77% phonemes correctly. The oldest brother (S12) could not yet perform open-set speech audiometry at that moment. CONCLUSIONS: Implant outcomes are better with normal inner ear anatomy in general. The earlier congenital patients are implanted, the better their outcomes. Here, we demonstrate both statements are true in a homozygous c.1342C > T p. (Arg448*) pathogenic variant in the TRIOBP gene in all 3 affected siblings.

Speech Perception Changes in the Acoustically Aided, Nonimplanted Ear after Cochlear Implantation: A Multicenter Study.

In recent years there has been an increasing percentage of cochlear implant (CI) users who have usable residual hearing in the contralateral, nonimplanted ear, typically aided by acoustic amplification. This raises the issue of the extent to which the signal presented through the cochlear implant may influence how listeners process information in the acoustically stimulated ear. This multicenter retrospective study examined pre- to postoperative changes in speech perception in the nonimplanted ear, the implanted ear, and both together. Results in the latter two conditions showed the expected increases, but speech perception in the nonimplanted ear showed a modest yet meaningful decrease that could not be completely explained by changes in unaided thresholds, hearing aid malfunction, or several other demographic variables. Decreases in speech perception in the nonimplanted ear were more likely in individuals who had better levels of speech perception in the implanted ear, and in those who had better speech perception in the implanted than in the nonimplanted ear. This raises the possibility that, in some cases, bimodal listeners may rely on the higher quality signal provided by the implant and may disregard or even neglect the input provided by the nonimplanted ear.

Cochlear implant telemedicine: Remote fitting based on psychoacoustic self-tests and artificial intelligence.

Objective: This study aims to assess the feasibility of autonomous cochlear implant (CI) fitting by adult CI recipients based on psychoacoustic self-testing and artificial intelligence (AI). Design: A feasibility study was performed on six adult CI recipients implanted with a Nucleus device. Two weeks after processor activation in the clinic, a 'self-fitting' session was organized in a supervised simulated home environment. The CI recipient performed pure tone audiometry and spectral discrimination tests as self-tests. The AI application FOX analysed the results and recommended a new map. The participants filled out a questionnaire and were tested again after 2 months of take-home experience. Results: Four out of six patients performed the self-tests without any help from the audiologist and four were fitted by FOX without any manual intervention. All patients were comfortable with the concept of self-testing and automated fitting. Patients acknowledged that at this stage the remote supervision of an audiologist remains essential. Conclusions: The study showed that audiological self-assessment and remote CI fitting with AI under the supervision of an audiologist is feasible, at least in a number of CI recipients. Currently, there are still some technical and regulatory challenges to be addressed before this can become routine practice.

Listening Difficulties of Children With Cochlear Implants in Mainstream Secondary Education.

OBJECTIVES: Previous research has shown that children with cochlear implants (CIs) encounter more communication difficulties than their normal-hearing (NH) peers in kindergarten and elementary schools. Yet, little is known about the potential listening difficulties that children with CIs may experience during secondary education. The aim of this study was to investigate the listening difficulties of children with a CI in mainstream secondary education and to compare these results to the difficulties of their NH peers and the difficulties observed by their teachers. DESIGN: The Dutch version of the Listening Inventory for Education Revised (LIFE-R) was administered to 19 children (mean age = 13 years 9 months; SD = 9 months) who received a CI early in life, to their NH classmates (n = 239), and to their teachers (n = 18). All participants were enrolled in mainstream secondary education in Flanders (first to fourth grades). The Listening Inventory for Secondary Education consists of 15 typical listening situations as experienced by students (LIFEstudent) during class activities (LIFEclass) and during social activities at school (LIFEsocial). The teachers completed a separate version of the Listening Inventory for Secondary Education (LIFEteacher) and Screening Instrument for Targeting Educational Risk. RESULTS: Participants with CIs reported significantly more listening difficulties than their NH peers. A regression model estimated that 75% of the participants with CIs were at risk of experiencing listening difficulties. The chances of experiencing listening difficulties were significantly higher in participants with CIs for 7 out of 15 listening situations. The 3 listening situations that had the highest chance of resulting in listening difficulties were (1) listening during group work, (2) listening to multimedia, and (3) listening in large-sized classrooms. Results of the teacher's questionnaires (LIFEteacher and Screening Instrument for Targeting Educational Risk) did not show a similar significant difference in listening difficulties between participants with a CI and their NH peers. According to teachers, NH participants even obtained significantly lower scores for staying on task and for participation in class than participants with a CI. CONCLUSIONS: Although children with a CI seemingly fit in well in mainstream schools, they still experience significantly more listening difficulties than their NH peers. Low signal to noise ratios (SNRs), distortions of the speech signal (multimedia, reverberation), distance, lack of visual support, and directivity effects of the microphones were identified as difficulties for children with a CI in the classroom. As teachers may not always notice these listening difficulties, a list of practical recommendations was provided in this study, to raise awareness among teachers and to minimize the difficulties.

From manual to artificial intelligence fitting: Two cochlear implant case studies.

Objective: To assess whether CI programming by means of a software application using artificial intelligence (AI), FOX®, may improve cochlear implant (CI) performance. Patients: Two adult CI recipients who had mixed auditory results with their manual fitting were selected for an AI-assisted fitting. Even after 17 months CI experience and 19 manual fitting sessions, the first subject hadn't developed open set word recognition. The second subject, after 9 months of manual fitting, had developed good open set word recognition, but his scores remained poor at soft and loud presentation levels. Main outcome measure(s): Cochlear implant fitting parameters, pure tone thresholds, bisyllabic word recognition, phonemic discrimination scores and loudness scaling curves. Results: For subject 1, a first approach trying to optimize the home maps by means of AI-proposed adaptations was not successful whereas a second approach based on the use of Automaps (an AI approach based on universal, i.e. population based group statistics) during 3 months allowed the development of open set word recognition. For subject 2, the word recognition scores improved at soft and loud intensities with the AI suggestions. The AI-suggested modifications seem to be atypical. Conclusions: The two case studies illustrate that adults implanted with manual CI fitting may experience an improvement in their auditory results with AI-assisted fitting.

Speech polar plots for different directionality settings of SONNET cochlear implant processor.

Objectives: The newest CI processor from MED-EL company, the SONNET, has two new directional microphone settings. Besides the Omnidirectional microphone mode, it has the possibility to switch to Natural or Adaptive directionality. Both new modes favour perception of sound coming from a front-facing direction compared to sounds from sources at alternate azimuths. Natural directionality mimics the pinna effect of the normal external ear. Design: We undertook to verify the effect of these options in vivo by means of clinical audiological tests. Speech reception thresholds were successively measured for a variety of speech presentation azimuths while keeping the noise azimuths constant. Complete 'Speech Reception Threshold (SRT)-Polar-Plots' were obtained from these data for the Omnidirectional and Natural directionality modes of the SONNET. In addition, one 'SRT-point' was also measured in the 'Adaptive' mode for speech coming from 45° azimuth. Study sample: A group of 13 adult CI recipients participated. Only one of these subjects had previous experience with the SONNET processor. Results: Complete 'SRT-Polar-Plots' could be measured in Natural and Omnidirectional modes in CI recipients within an acceptable timeframe. The pinna-following directionality for Natural mode could be confirmed. Median SRT in noise for speech coming from the 45° azimuth speaker was -5.6 dB SNR for Omnidirectional, -9.1 dB SNR for Natural and -12.8 dB SNR for Adaptive microphone. Natural and Adaptive significantly improved performance compared to Omnidirectional mode at this optimal azimuth of 45° with a median improvement in SRT of 3.5 and 7.2 dB respectively. Conclusions: A novel audiological method, 'SRT-Polar-Plot', was developed and described. Significant directionality benefits for Natural and Adaptive mode were confirmed in vivo using this technique.

Empowering Senior Cochlear Implant Users at Home via a Tablet Computer Application.

PURPOSE: The introduction of connectivity technologies in hearing implants allows new ways to support cochlear implant (CI) users remotely. Some functionalities and services that are traditionally only available in an in-clinic care model can now also be accessed at home. This study explores the feasibility of a prototype of a tablet computer application (MyHearingApp [MHA]) in a group of senior experienced CI users at home, evaluating usability and user motivation. METHOD: Based on user feedback, a tablet computer application (MHA) for the Cochlear Nucleus 6 CP910 sound processor was designed implementing six different functionalities: (a) My Hearing Tests, (b) My Environment, (c) My Hearing Journey, (d) Tip of the Day, (e) Recipient Portal, and (f) Program Use and Events. The clinical evaluation design was a prospective study of the MHA in 16 senior experienced CI users. During 4 weeks, participants could freely explore the functionalities. At the end, the usability and their motivation for uptake and adherence were measured using a baseline and follow-up questionnaire. RESULTS: Based on the System Usability Score (as part of the follow-up questionnaire), a good level of usability was indicated (M = 75.6, range: 62.5-92.5, SD = 8.6). The ability to perform hearing tests at home is ranked as the most relevant functionality within the MHA. According to the Intrinsic Motivation Inventory (Deci, Eghrari, Patrick, & Leone, 1994) questionnaire (as part of the follow-up questionnaire), participants reported high levels of interest and enjoyment, found themselves competent, and did not experience pressure while working with the app. CONCLUSIONS: This study evaluated a tablet computer application (MHA) for experienced senior CI users by means of a prospective design, which provided novel insights into delivering CI care into the home of the CI user. The user feedback from this small-scale study suggests that the participants are open to take more responsibility for and to become a more active actor in their own hearing care, if only this is facilitated with the right tools. This may foster the evolution from a clinic-led to a more patient-centered care model, where CI users feel more empowered in the self-management of their hearing implant device.

LiCoS: A New Linguistically Controlled Sentences Test to Assess Functional Hearing Performance.

PURPOSE: To overcome the potential tension between clinical and ecological validity in speech audiometric assessment by creating a new set of sentence materials with high linguistic validity for the Dutch-speaking area. METHODS: A linguistic "fingerprint" of modern spoken Dutch and Flemish served to generate a set of sentences recorded from 1 male and 1 female talker. The sentences were presented to 30 normal-hearing listeners in stationary speech noise at a signal-to-noise ratio (SNR) of -5 dB sound pressure level (SPL). A list design criterion was used to achieve perceptive homogeneity across the test lists, by scrambling lists of sentences of different syntactic types while controlling for linguistic complexity. The original set of test materials was narrowed down to 360 sentences, and list equivalency was evaluated at the audiological and linguistic levels. A psychometric curve was generated with a resolution of 2 dB based on a second group of 60 young normal-hearing native speakers of Dutch and Flemish. RESULTS: Sentence understanding showed an average repetition accuracy of 63.40% (SD 1.01) across the lists at an SNR of -5 dB SPL. No significant differences were found between the lists at the level of the individual listener. At the linguistic level, the sentence lists showed an equal distribution of phonological, morphological, and syntactic features. CONCLUSION: LiCoS combines the clinical benefit of acoustic control at the list level with the high ecological validity of linguistically representative test items. The new speech audiometric test is particularly appropriate to assess sentence understanding in individuals who would otherwise exhibit near-ceiling performance when tested with linguistically more simplified test stimuli. In combination with pure tone audiometric assessment, LiCoS provides valuable complementary information with respect to the functional hearing of patients.

Speech understanding in noise in elderly adults: the effect of inhibitory control and syntactic complexity.

BACKGROUND: Previous research has suggested that speech perception in elderly adults is influenced not only by age-related hearing loss or presbycusis but also by declines in cognitive abilities, by background noise and by the syntactic complexity of the message. AIMS: To gain further insight into the influence of these cognitive as well as acoustic and linguistic factors on speech perception in elderly adults by investigating inhibitory control as a listener characteristic and background noise type and syntactic complexity as input characteristics. METHODS & PROCEDURES: Phoneme identification was measured in different noise conditions and in different linguistic contexts (single words, sentences with varying syntactic complexity). Additionally, inhibitory control was measured using a visual stimulus-response matching task. Fifty-one adults participated in this study, including elderly adults with age-related hearing loss (n = 9) and with normal hearing (n = 17), and a control group of normal hearing younger adults (n = 25). OUTCOMES & RESULTS: The analysis revealed that elderly adults with normal hearing and with hearing loss were less likely to identify successfully phonemes in single words than younger normal hearing controls. In the context of sentences, only elderly adults with hearing loss had a lower odds of correct phoneme perception than the control group. Additionally, in elderly adults with hearing loss, phoneme-in-sentence perception was linked to age-related declines in inhibitory control. In all participants, phoneme identification in sentences was influenced by both noise type and syntactic complexity. CONCLUSIONS & IMPLICATIONS: Inhibitory control and syntactic complexity might play a significant role in speech perception, especially in elderly listeners. These factors might also influence the results of clinical assessments of speech perception. Testing procedures thus need to be selected and their results interpreted carefully with these influences in mind.

The use of cochlear's SCAN and wireless microphones to improve speech understanding in noise with the Nucleus6® CP900 processor.

OBJECTIVES: The newest Nucleus CI processor, the CP900, has two new options to improve speech-in-noise perception: (1) use of an adaptive directional microphone (SCAN mode) and (2) wireless connection to MiniMic1 and MiniMic2 wireless remote microphones. DESIGN: An analysis was made of the absolute and relative benefits of these technologies in a real-world mimicking test situation. Speech perception was tested using an adaptive speech-in-noise test (sentences-in-babble noise). In session A, SRTs were measured in three conditions: (1) Clinical Map, (2) SCAN and (3) MiniMic1. Each was assessed for three distances between speakers and CI recipient: 1 m, 2 m and 3 m. In session B, the benefit of the use of MiniMic2 was compared to benefit of MiniMic1 at 3 m. STUDY SAMPLE: A group of 13 adult CP900 recipients participated. RESULTS: SCAN and MiniMic1 improved performance compared to the standard microphone with a median improvement in SRT of 2.7-3.9 dB for SCAN at 1 m and 3 m, respectively, and 4.7-10.9 dB for the MiniMic1. MiniMic1 improvements were significant. MiniMic2 showed an improvement in SRT of 22.2 dB compared to 10.0 dB for MiniMic1 (3 m). CONCLUSIONS: Digital wireless transmission systems (i.e. MiniMic) offer a statistically and clinically significant improvement in speech perception in challenging, realistic listening conditions.

Computer-assisted CI fitting: Is the learning capacity of the intelligent agent FOX beneficial for speech understanding?

OBJECTIVE: The software application FOX ('Fitting to Outcome eXpert') is an intelligent agent to assist in the programing of cochlear implant (CI) processors. The current version utilizes a mixture of deterministic and probabilistic logic which is able to improve over time through a learning effect. This study aimed at assessing whether this learning capacity yields measurable improvements in speech understanding. METHODS: A retrospective study was performed on 25 consecutive CI recipients with a median CI use experience of 10 years who came for their annual CI follow-up fitting session. All subjects were assessed by means of speech audiometry with open set monosyllables at 40, 55, 70, and 85 dB SPL in quiet with their home MAP. Other psychoacoustic tests were executed depending on the audiologist's clinical judgment. The home MAP and the corresponding test results were entered into FOX. If FOX suggested to make MAP changes, they were implemented and another speech audiometry was performed with the new MAP. RESULTS: FOX suggested MAP changes in 21 subjects (84%). The within-subject comparison showed a significant median improvement of 10, 3, 1, and 7% at 40, 55, 70, and 85 dB SPL, respectively. All but two subjects showed an instantaneous improvement in their mean speech audiometric score. DISCUSSION: Persons with long-term CI use, who received a FOX-assisted CI fitting at least 6 months ago, display improved speech understanding after MAP modifications, as recommended by the current version of FOX. This can be explained only by intrinsic improvements in FOX's algorithms, as they have resulted from learning. This learning is an inherent feature of artificial intelligence and it may yield measurable benefit in speech understanding even in long-term CI recipients.

Linguistic Factors Influencing Speech Audiometric Assessment.

In speech audiometric testing, hearing performance is typically measured by calculating the number of correct repetitions of a speech stimulus. We investigate to what extent the repetition accuracy of Dutch speech stimuli presented against a background noise is influenced by nonauditory processes. We show that variation in verbal repetition accuracy is partially explained by morpholexical and syntactic features of the target language. Verbs, prepositions, conjunctions, determiners, and pronouns yield significantly lower correct repetitions than nouns, adjectives, or adverbs. The reduced repetition performance for verbs and function words is probably best explained by the similarities in the perceptual nature of verbal morphology and function words in Dutch. For sentences, an overall negative effect of syntactic complexity on speech repetition accuracy was found. The lowest number of correct repetitions was obtained with passive sentences, reflecting the cognitive cost of processing a noncanonical sentence structure. Taken together, these findings may have important implications for the audiological practice. In combination with hearing loss, linguistic complexity may increase the cognitive demands to process sentences in noise, leading to suboptimal functional hearing in day-to-day listening situations. Using test sentences with varying degrees of syntactic complexity may therefore provide useful information to measure functional hearing benefits.

Expert opinion: Time to ban formal CI selection criteria?

This contribution addresses cochlear implantation (CI) selection criteria as a discussion topic. It expresses a personal viewpoint that challenges the usefulness and necessity of formal selection criteria. Scientifically, it is argued that CI selection must be highly individual, whereas the current criteria are general, not valid, not based on a wide consensus, and not up-to-date. Morally, it is argued that it is not legitimate to presume equality between patients and CI centers, that the current selection criteria create an ethical dilemma, and that an unresolvable contradiction exists between quality of life and measurability. Finally, liberalizing the criteria would probably have only a minimal impact on current practice and budget.

Speech understanding in noise with the Roger Pen, Naida CI Q70 processor, and integrated Roger 17 receiver in a multi-talker network.

Roger is a digital adaptive multi-channel remote microphone technology that wirelessly transmits a speaker's voice directly to a hearing instrument or cochlear implant sound processor. Frequency hopping between channels, in combination with repeated broadcast, avoids interference issues that have limited earlier generation FM systems. This study evaluated the benefit of the Roger Pen transmitter microphone in a multiple talker network (MTN) for cochlear implant users in a simulated noisy conversation setting. Twelve post-lingually deafened adult Advanced Bionics CII/HiRes 90K recipients were recruited. Subjects used a Naida CI Q70 processor with integrated Roger 17 receiver. The test environment simulated four people having a meal in a noisy restaurant, one the CI user (listener), and three companions (talkers) talking non-simultaneously in a diffuse field of multi-talker babble. Speech reception thresholds (SRTs) were determined without the Roger Pen, with one Roger Pen, and with three Roger Pens in an MTN. Using three Roger Pens in an MTN improved the SRT by 14.8 dB over using no Roger Pen, and by 13.1 dB over using a single Roger Pen (p < 0.0001). The Roger Pen in an MTN provided statistically and clinically significant improvement in speech perception in noise for Advanced Bionics cochlear implant recipients. The integrated Roger 17 receiver made it easy for users of the Naida CI Q70 processor to take advantage of the Roger system. The listening advantage and ease of use should encourage more clinicians to recommend and fit Roger in adult cochlear implant patients.