Similar gaze behaviour during dialogue perception in congenitally deaf children with cochlear Implants and normal hearing children.

BACKGROUND: Perceptual and speech production abilities of children with cochlear implants (CIs) are usually tested by word and sentence repetition or naming tests. However, these tests are quite far apart from daily life linguistic contexts. AIM: Here, we describe a way of investigating the link between language comprehension and anticipatory verbal behaviour promoting the use of more complex listening situations. METHODS AND PROCEDURE: The setup consists in watching the audio-visual dialogue of two actors. Children's gaze switches from one speaker to the other serve as a proxy of their prediction abilities. Moreover, to better understand the basis and the impact of anticipatory behaviour, we also measured children's ability to understand the dialogue content, their speech perception and memory skills as well as their rhythmic skills, that also require temporal predictions. Importantly, we compared children with CI performances with those of an age-matched group of children with normal hearing (NH). OUTCOMES AND RESULTS: While children with CI revealed poorer speech perception and verbal working memory abilities than NH children, there was no difference in gaze anticipatory behaviour. Interestingly, in children with CI only, we found a significant correlation between dialogue comprehension, perceptual skills and gaze anticipatory behaviour. CONCLUSION: Our results extend to a dialogue context of previous findings showing an absence of predictive deficits in children with CI. The current design seems an interesting avenue to provide an accurate and objective estimate of anticipatory language behaviour in a more ecological linguistic context also with young children. WHAT THIS PAPER ADDS: What is already known on the subject Children with cochlear implants seem to have difficulties extracting structure from and learning sequential input patterns, possibly due to signal degradation and auditory deprivation in the first years of life. They also seem to have a reduced use of contextual information and slow language processing among children with hearing loss. What this paper adds to existing knowledge Here we show that when adopting a rather complex linguistic context such as watching a dialogue of two individuals, children with cochlear implants are able to use the speech and language structure to anticipate gaze switches to the upcoming speaker. What are the clinical implications of this work? The present design seems an interesting avenue to provide an accurate and objective estimate of anticipatory behaviour in a more ecological and dynamic linguistic context. Importantly, this measure is implicit and it has been previously used with very young (normal-hearing) children, showing that they spontaneously make anticipatory gaze switches by age two. Thus, this approach may be of interest to refine the speech comprehension assessment at a rather early age after cochlear implantation where explicit behavioural tests are not always reliable and sensitive.

Intensive Training of Spatial Hearing Promotes Auditory Abilities of Bilateral Cochlear Implant Adults: A Pilot Study.

OBJECTIVE: The aim of this study was to evaluate the feasibility of a virtual reality-based spatial hearing training protocol in bilateral cochlear implant (CI) users and to provide pilot data on the impact of this training on different qualities of hearing. DESIGN: Twelve bilateral CI adults aged between 19 and 69 followed an intensive 10-week rehabilitation program comprised eight virtual reality training sessions (two per week) interspersed with several evaluation sessions (2 weeks before training started, after four and eight training sessions, and 1 month after the end of training). During each 45-minute training session, participants localized a sound source whose position varied in azimuth and/or in elevation. At the start of each trial, CI users received no information about sound location, but after each response, feedback was given to enable error correction. Participants were divided into two groups: a multisensory feedback group (audiovisual spatial cue) and an unisensory group (visual spatial cue) who only received feedback in a wholly intact sensory modality. Training benefits were measured at each evaluation point using three tests: 3D sound localization in virtual reality, the French Matrix test, and the Speech, Spatial and other Qualities of Hearing questionnaire. RESULTS: The training was well accepted and all participants attended the whole rehabilitation program. Four training sessions spread across 2 weeks were insufficient to induce significant performance changes, whereas performance on all three tests improved after eight training sessions. Front-back confusions decreased from 32% to 14.1% ( p = 0.017); speech recognition threshold score from 1.5 dB to -0.7 dB signal-to-noise ratio ( p = 0.029) and eight CI users successfully achieved a negative signal-to-noise ratio. One month after the end of structured training, these performance improvements were still present, and quality of life was significantly improved for both self-reports of sound localization (from 5.3 to 6.7, p = 0.015) and speech understanding (from 5.2 to 5.9, p = 0.048). CONCLUSIONS: This pilot study shows the feasibility and potential clinical relevance of this type of intervention involving a sensorial immersive environment and could pave the way for more systematic rehabilitation programs after cochlear implantation.

Reaching to Sounds Improves Spatial Hearing in Bilateral Cochlear Implant Users.

OBJECTIVES: We assessed if spatial hearing training improves sound localization in bilateral cochlear implant (BCI) users and whether its benefits can generalize to untrained sound localization tasks. DESIGN: In 20 BCI users, we assessed the effects of two training procedures (spatial versus nonspatial control training) on two different tasks performed before and after training (head-pointing to sound and audiovisual attention orienting). In the spatial training, participants identified sound position by reaching toward the sound sources with their hand. In the nonspatial training, comparable reaching movements served to identify sound amplitude modulations. A crossover randomized design allowed comparison of training procedures within the same participants. Spontaneous head movements while listening to the sounds were allowed and tracked to correlate them with localization performance. RESULTS: During spatial training, BCI users reduced their sound localization errors in azimuth and adapted their spontaneous head movements as a function of sound eccentricity. These effects generalized to the head-pointing sound localization task, as revealed by greater reduction of sound localization error in azimuth and more accurate first head-orienting response, as compared to the control nonspatial training. BCI users benefited from auditory spatial cues for orienting visual attention, but the spatial training did not enhance this multisensory attention ability. CONCLUSIONS: Sound localization in BCI users improves with spatial reaching-to-sound training, with benefits to a nontrained sound localization task. These findings pave the way to novel rehabilitation procedures in clinical contexts.

A new tool for the assessment of speech understanding and spatial hearing difficulties in children: the Kid-SSQ questionnaire.

PURPOSE: To develop and validate a new questionnaire, the Kid-SSQ, for the rapid screening of hearing abilities in children with hearing impairment, aged 7-17 years. METHODS: The questionnaire was constructed from two existing, validated versions of the 'Speech, Spatial and Qualities of Hearing' - (SSQ) questionnaire (pediatric form and adult short-form). The 12 selected items included auditory aspects from three subscales: speech perception, spatial hearing, and qualities of hearing. This new short form was then validated in 154 children with cochlear implants (100 bilaterally, and 54 unilaterally implanted children). Construct validity was assessed by testing relationships between Kid-SSQ scores and objective clinical parameters (e.g., age at test, pure-tone audiometry-PTA threshold, speech reception threshold-SRT, duration of binaural experience). RESULTS: Completion time was acceptable for use with children (less than 10 min) and the non-response rate was less than 1%. Good internal consistency was obtained (Cronbach's α = 0.78), with a stable internal structure corresponding to the 3 intended subscales. External validity showed the specificity of each subscale: speech subscale scores were significantly predicted (r = 0.32, p < 0.001) by both 2 kHz PTA threshold (ß = 0.33, p < 0.001) and SRT (ß = - 0.23, p < 0.001). Children with more binaural experience showed significantly higher scores on the spatial subscale than children with less binaural experience (F(1,98) = 5.1, p < 0.03) and the qualities of hearing subscale scores significantly depended on both age and SRT (r = 0.32, p < 0.001). CONCLUSIONS: The Kid-SSQ questionnaire is a robust and clinically useful questionnaire for self-assessment of difficulties in various auditory domains.

Training spatial hearing in unilateral cochlear implant users through reaching to sounds in virtual reality.

BACKGROUND AND PURPOSE: Use of unilateral cochlear implant (UCI) is associated with limited spatial hearing skills. Evidence that training these abilities in UCI user is possible remains limited. In this study, we assessed whether a Spatial training based on hand-reaching to sounds performed in virtual reality improves spatial hearing abilities in UCI users METHODS: Using a crossover randomized clinical trial, we compared the effects of a Spatial training protocol with those of a Non-Spatial control training. We tested 17 UCI users in a head-pointing to sound task and in an audio-visual attention orienting task, before and after each training.
Study is recorded in clinicaltrials.gov (NCT04183348). RESULTS: During the Spatial VR training, sound localization errors in azimuth decreased. Moreover, when comparing head-pointing to sounds before vs. after training, localization errors decreased after the Spatial more than the control training. No training effects emerged in the audio-visual attention orienting task. CONCLUSIONS: Our results showed that sound localization in UCI users improves during a Spatial training, with benefits that extend also to a non-trained sound localization task (generalization). These findings have potentials for novel rehabilitation procedures in clinical contexts.

Spatial Hearing Difficulties in Reaching Space in Bilateral Cochlear Implant Children Improve With Head Movements.

OBJECTIVES: The aim of this study was to assess three-dimensional (3D) spatial hearing abilities in reaching space of children and adolescents fitted with bilateral cochlear implants (BCI). The study also investigated the impact of spontaneous head movements on sound localization abilities. DESIGN: BCI children (N = 18, aged between 8 and 17) and age-matched normal-hearing (NH) controls (N = 18) took part in the study. Tests were performed using immersive virtual reality equipment that allowed control over visual information and initial eye position, as well as real-time 3D motion tracking of head and hand position with subcentimeter accuracy. The experiment exploited these technical features to achieve trial-by-trial exact positioning in head-centered coordinates of a single loudspeaker used for real, near-field sound delivery, which was reproducible across trials and participants. Using this novel approach, broadband sounds were delivered at different azimuths within the participants' arm length, in front and back space, at two different distances from their heads. Continuous head-monitoring allowed us to compare two listening conditions: "head immobile" (no head movements allowed) and "head moving" (spontaneous head movements allowed). Sound localization performance was assessed by computing the mean 3D error (i.e. the difference in space between the X-Y-Z position of the loudspeaker and the participant's final hand position used to indicate the localization of the sound's source), as well as the percentage of front-back and left-right confusions in azimuth, and the discriminability between two nearby distances. Several clinical factors (i.e. age at test, interimplant interval, and duration of binaural experience) were also correlated with the mean 3D error. Finally, the Speech Spatial and Qualities of Hearing Scale was administered to BCI participants and their parents. RESULTS: Although BCI participants distinguished well between left and right sound sources, near-field spatial hearing remained challenging, particularly under the " head immobile" condition. Without visual priors of the sound position, response accuracy was lower than that of their NH peers, as evidenced by the mean 3D error (BCI: 55 cm, NH: 24 cm, p = 0.008). The BCI group mainly pointed along the interaural axis, corresponding to the position of their CI microphones. This led to important front-back confusions (44.6%). Distance discrimination also remained challenging for BCI users, mostly due to sound compression applied by their processor. Notably, BCI users benefitted from head movements under the "head moving" condition, with a significant decrease of the 3D error when pointing to front targets (p < 0.001). Interimplant interval was correlated with 3D error (p < 0.001), whereas no correlation with self-assessment of spatial hearing difficulties emerged (p = 0.9). CONCLUSIONS: In reaching space, BCI children and adolescents are able to extract enough auditory cues to discriminate sound side. However, without any visual cues or spontaneous head movements during sound emission, their localization abilities are substantially impaired for front-back and distance discrimination. Exploring the environment with head movements was a valuable strategy for improving sound localization within individuals with different clinical backgrounds. These novel findings could prompt new perspectives to better understand sound localization maturation in BCI children, and more broadly in patients with hearing loss.

Feasibility of day-case pediatric cochlear implantation.

PURPOSE: Pediatric cochlear implantation is performed on an outpatient basis in an inconstant way. The aim of this study is to assess the feasibility of day-case pediatric cochlear implantation by determining the acceptability of outpatient-to-inpatient conversion rate (acceptability threshold of 5%) and to assess the safety by comparing outpatient and inpatient postoperative events. We also want to identify conversion predictive factors. METHODS: We conducted a monocentric retrospective study including 267 cases aged 6 months to 18 years who underwent unilateral cochlear implantation between 2016 and 2020. This population was divided into two groups: outpatient group (190 cases) and inpatient group (77 cases). RESULTS: Among the 190 cases scheduled as day surgery, 9 cases required conversion to conventional hospitalization which leads to an outpatient-to-inpatient conversion rate of 4.7%. Postoperative nausea and vomiting (PONV) were involved in all cases of conversion. Conversion predictive factors were the presence of an inner ear malformation at risk of gusher (OR 32.51, 95% CI [4.98-370.27], p 0.001) and the intraoperative administration of morphine (OR 8.52, 95% CI [1.38-86.84], p 0.035). There was no statistically significant difference in immediate postoperative complications (outpatient 14.2% vs inpatient 16.9% p 0.715), early-stage complications (outpatient 12.6% vs inpatient 10.4% p 0.812) and early-stage unplanned consultations (outpatient 4.7% vs inpatient 3.9% p 0.748) between outpatient and inpatient groups. Unplanned readmissions were found only in the outpatient group. CONCLUSION: Day-case pediatric cochlear implantation is a feasible and safe procedure even in infants. The outpatient-to-inpatient conversion rate of 4.7% is considered acceptable but requires anticipation of human and accommodation needs. No causes of conversion were life-threatening. The risk of postoperative complications and unplanned consultations are not influenced by the mode of hospitalization. Special attention should be paid to the prevention of PONV and the presence of inner ear malformations.

Rhythmic Abilities of Children With Hearing Loss.

OBJECTIVES: Children with hearing loss (HL), in spite of early cochlear implantation, often struggle considerably with language acquisition. Previous research has shown a benefit of rhythmic training on linguistic skills in children with HL, suggesting that improving rhythmic capacities could help attenuating language difficulties. However, little is known about general rhythmic skills of children with HL and how they relate to speech perception. The aim of this study is twofold: (1) to assess the abilities of children with HL in different rhythmic sensorimotor synchronization tasks compared to a normal-hearing control group and (2) to investigate a possible relation between sensorimotor synchronization abilities and speech perception abilities in children with HL. DESIGN: A battery of sensorimotor synchronization tests with stimuli of varying acoustic and temporal complexity was used: a metronome, different musical excerpts, and complex rhythmic patterns. Synchronization abilities were assessed in 32 children (aged from 5 to 10 years) with a severe to profound HL mainly fitted with one or two cochlear implants (n = 28) or with hearing aids (n = 4). Working memory and sentence repetition abilities were also assessed. Performance was compared to an age-matched control group of 24 children with normal hearing. The comparison took into account variability in working memory capacities. For children with HL only, we computed linear regressions on speech, sensorimotor synchronization, and working memory abilities, including device-related variables such as onset of device use, type of device, and duration of use. RESULTS: Compared to the normal-hearing group, children with HL performed poorly in all sensorimotor synchronization tasks, but the effect size was greater for complex as compared to simple stimuli. Group differences in working memory did not explain this result. Linear regression analysis revealed that working memory, synchronization to complex rhythms performances, age, and duration of device use predicted the number of correct syllables produced in a sentence repetition task. CONCLUSION: Despite early cochlear implantation or hearing aid use, hearing impairment affects the quality of temporal processing of acoustic stimuli in congenitally deaf children. This deficit seems to be more severe with stimuli of increasing rhythmic complexity highlighting a difficulty in structuring sounds according to a temporal hierarchy.

Multi-operated cholesteatoma: when two surgeries are not enough.

PURPOSE: Most studies regarding residual and recurrent cholesteatoma focus on single relapse. This study examines patients who had to undergo at least three surgeries for complete eradication of their cholesteatoma, with the aim of bringing to light risk factors and assessing the functional impact of multiple surgeries on hearing. METHOD: We include 27 patients who underwent 3 consecutive surgeries for cholesteatoma between 2006 and 2016. This population represented 3.1% of all cholesteatoma operated on during that same period (868 patients). RESULTS: Cases of multi-residual and/or recurrent cholesteatoma (RRC) were significantly younger (13.1 years old), than single-RRC or cases with No-RRC (respectively, 28.0 and 38.5 years old) (p < 0.01). Furthermore, there was a significant difference in cholesteatoma location especially for combined attical and mesotympanic location between the three groups (no-RCC 26%; single-RRC 34% and multi-RRC 66%) (p < 0.01). There was also a significant difference in ossicular erosion of the malleus, incus and stapes between the three groups (p < 0.01). In our study, the type of surgery did not influence multi-RRC rates. We did not observe any significant impact on hearing between the first and third surgeries. Mean duration between the first and second surgeries was significantly shorter for multi-RRC (14.5 months SD 8.3) than for single-RRC (23.3 months SD 18.1) (p < 0.05). CONCLUSION: Special care should be given in case of combined attical and mesotympanic extension, ossicular erosion and young children. Delaying the realization of MRI, and/or of second-look surgery, could decrease the risk of multi-RRC.