Contralateral Routing Of Signal Research Articles

Masked Speech Perception with Bone Conduction Device, Contralateral Routing of Signals Hearing Aid, and Cochlear Implant Use in Adults with Single-Sided Deafness: A Prospective Hearing Device Comparison using a Unified Testing Framework

Introduction: For the treatment of single-sided deafness (SSD), common treatment choices include a contralateral routing of signals (CROS) hearing aid, a bone conduction device (BCD), and a cochlear implant (CI). The primary aim of this study was to compare speech understanding in noise and binaural benefits in adults with postlingual SSD between preoperative unaided baseline, preoperative CROS and BCD trial devices, and CI, following recommendations from a consensus protocol. In addition, we investigated the effect of masker type on speech understanding. Methods: This was a prospective study with twelve participants. Binaural effects of head shadow, squelch, summation, and spatial release from masking were assessed by measuring speech reception thresholds (SRTs) in five different spatial target-masker configurations using two different maskers: two-talker babble (TTB), and speech-shaped noise (SSN). Preoperatively, participants were assessed unaided and with CROS and BCD trial devices. After cochlear implantation, participants were assessed at 1, 3, and 6 months post-activation. Results: For TTB, significant improvements in SRT with a CI relative to preoperatively unaided were found in all spatial configurations. With CI at 6 months, median benefits were 7.8 dB in S_SSDN_AH and 5.1 dB in S₀N_AH (head shadow), 3.4 dB in S₀N₀ (summation), and 4.6 dB in S₀N_SSD and 5.1 dB in S_AHN_SSD (squelch). CROS yielded a significant head shadow benefit of 2.4 dB in S_SSDN_AH and a significant deterioration in squelch of 2.5 dB in S₀N_SSD and S_AHN_SSD, but no summation effect. With BCD, there was a significant summation benefit of 1.5 dB, but no head shadow nor squelch effect. For SSN, significant improvements in SRT with CI compared to preoperatively unaided were found in three spatial configurations. Median benefits with CI at 6 months were: 8.5 dB in S_SSDN_AH and 4.6 dB in S₀N_AH (head shadow), 1.4 dB in S₀N₀ (summation), but no squelch. CROS showed a significant head shadow benefit of 1.7 dB in S_SSDN_AH, but no summation effect, and a significant deterioration in squelch of 2.9 dB in S₀N_SSD and 3.2 dB in S_AHN_SSD. With BCD, no binaural effect was obtained. Longitudinally, we found significant head shadow benefits with a CI in S_SSDN_AH in both maskers at all postoperative intervals and in S₀N_AH at 3 and 6 months post-activation. Conclusion: With a CI, a clear benefit for masked speech perception was observed for all binaural effects. Benefits with CROS and BCD were more limited. CROS usage was detrimental to the squelch effect.

Single-Sided Deafness and Hearing Rehabilitation Modalities: Contralateral Routing of Signal Devices, Bone Conduction Devices, and Cochlear Implants.

Single sided deafness (SSD) is characterized by significant sensorineural hearing loss, severe or profound, in only one ear. SSD adversely affects various aspects of auditory perception, including causing impairment in sound localization, difficulties with speech comprehension in noisy environments, and decreased spatial awareness, resulting in a significant decline in overall quality of life (QoL). Several treatment options are available for SSD, including cochlear implants (CI), contralateral routing of signal (CROS), and bone conduction devices (BCD). The lack of consensus on outcome domains and measurement tools complicates treatment comparisons and decision-making. This narrative overview aims to summarize the treatment options available for SSD in adult and pediatric populations, discussing their respective advantages and disadvantages. Rerouting devices (CROS and BCD) attenuate the effects of head shadow and improve sound awareness and signal-to-noise ratio in the affected ear; however, they cannot restore binaural hearing. CROS devices, being non-implantable, are the least invasive option. Cochlear implantation is the only strategy that can restore binaural hearing, delivering significant improvements in speech perception, spatial localization, tinnitus control, and overall QoL. Comprehensive preoperative counseling, including a discussion of alternative technologies, implications of no treatment, expectations, and auditory training, is critical to optimizing therapeutic outcomes.

Cochlear Implants for Children with Unilateral Hearing Loss: Debunking the Myths

Cochlear implants (CIs) have revolutionized the field of audiology, providing a life-changing solution for children with bilateral profound hearing loss. Expanding criteria has allowed children with significant unilateral hearing loss (UHL) to benefit from this technology as well. The practice is not without controversy, however. While we have known since 1984 that children with UHL face educational challenges (Bess & Tharpe, 1984, 1986), watchful waiting until a child is old enough to be fitted with a Contralateral Routing of Signal (CROS) device has been the status quo (Bagatto, 2020; Bagatto et al., 2019). While research has continued to establish the benefits of cochlear implantation in this population, it has yet to become the standard of care. As is inherent in controversial practices, several myths and misconceptions surrounding the use of CIs for children with UHL pervade clinical hearing care systems. Here, we will debunk these myths by examining the evidence-based benefits and considerations associated with cochlear implantation in children with UHL. Through an analysis of current research and clinical evidence, we will highlight the potential advantages of CIs as a viable treatment option, promoting informed decision-making and improving the quality of life for children with UHL.

A Feasible Sound Field Measurement in ENT Clinics for Contralateral Routing of Signals Hearing Aids: A Pilot Study

Background and Objectives The hearing in noise test (HINT) or sound localization test (SLT) is used as the standardized assessment for contralateral routing of signals (CROS) and bilateral microphones with contralateral routing of signals (BiCROS) hearing aids (HAs). However, implementing HINT or SLT can be challenging in most ENT clinics. In this study, we propose a new feasible method specifically designed for conducting a sound field hearing test for CROS and BiCROS HA users.Subjects and Method CROS/BiCROS HA users who visited Seoul St. Mary’s hospital between 2019 and 2021 were enrolled for the study. SLT was conducted in a sound-proof room equipped with two speakers positioned at a 45° angle from the patient on each side: noise stimuli were presented to the better ear the headphone patient was wearing while signals were presented to the worse ear via the speakers in the room. To validate the sound field test, a correlation analysis was conducted using the Bern benefit in single-sided deafness and the Korean version of the International Outcome Inventory for Hearing Aids (K-IOI-HA) Questionnaires.Results The aided speech discrimination score was significantly higher in the signal 60 dB HL/masking 50 dB HL condition than 50 dB HL/masking 50 dB HL condition (<i>p</i><0.05). A significant correlation was found between the gain of sound field speech audiometry and the K-IOI-HA questionnaire (<i>p</i><0.05).Conclusion Our novel sound field hearing test for CROS/BiCROS HA users, which presents appropriate noise stimuli via headphones to the better ear, appears to be a feasible approach for CROS/BiCROS HA users.

Hearing Aid in Vestibular-Schwannoma-Related Hearing Loss: A Review.

(1) Background: Several types of hearing aids are available for the rehabilitation of vestibular-schwannoma (VS)-related hearing loss. There is a lack of recently published papers regarding this theme. The aim of the present work is to organize current knowledge. (2) Methods: A review of the literature regarding the topics "vestibular schwannoma", "hearing loss", and "hearing aid" was performed. Nineteen studies were thus considered. (3) Results: Conventional hearing aids, contralateral routing of signal (CROS) aids, bone anchored hearing aids (BAHA), and others are available options for hearing rehabilitation in VS patients. The speech discrimination score (SDS) is considered the best measure to assess candidacy for rehabilitation with hearing aids. The best hearing rehabilitative conditions in VS patients when using conventional hearing aid devices are a mild-moderate hearing loss degree with good word recognition (more than 50% SDS). CROS-Aid and BAHA are reported to be beneficial. CROS-Aid expands on the area of receiving hearing. BAHA aids use direct bone-conduction stimulation. Unfortunately, there are no available studies focused specifically on VS patients that compare CROS and BAHA technologies. (4) Conclusions: Hearing aids, CROS, and BAHA are viable options for rehabilitating hearing impairment in VS, but require an accurate case-by-case audiological evaluation for rehabilitating hearing impairment in VS. Further studies are needed to prove if what is currently known about similar hearing illnesses can be confirmed, particularly in the case of VS.

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.

Speech Perception in Noise and Sound Localization for Cochlear Implant With Single-Sided Deafness Compared With Contralateral Routing of Signal Hearing Aids.

Cochlear implantation (CI) for the treatment of single-sided deafness (SSD) is a relatively new treatment modality. Although comparing the effectiveness of CI and contralateral routing of signal (CROS) hearing aids (HAs) is important, very few reports on this topic exist. In this study, objective assessments and subjective assessments were conducted to determine which SSD individuals would prefer CI or CROS HAs. Objective assessments (speech perception and sound localization) and subjective assessments (Hearing Handicap Inventory for Adults (HHIA), Abbreviated Profile of Hearing Aid Benefit (APHAB), MOS Short-Form 36-Item Health Survey version 2 (SF-36v2)) were performed on 87 SSD patients. Of the 87 SSD patients, 33 patients hoped for CROS HAs, and 17 patients hoped for CI. The CI group underwent subjective and objective assessments at 6 and 12 months postoperatively. The CROS HAs group underwent objective assessments at 1 month after wearing CROS HAs. After the intervention, the localization ability was significantly improved in the CI group (p < 0.05) with no significant improvement in that of the CROS HAs group (p = 0.48). No significant improvement in speech perception in noise was observed in the CROS (Signal-to-Noise ratio + 10, p = 0.08; SN + 0, p = 0.17); however, a significant improvement in the CI group was observed at 12 months postoperatively. The APHAB subscale "background noise" and SF-36v2 health concepts of role-physical, general health, vitality, role-emotional, and mental health were significantly higher in the CI group. CI was superior to CROS HAs in speech perception in terms of noise and sound localization. Patients with postlingual acute-onset hearing loss and more handicaps and a more positive view of their hearing loss possibly tend to choose CI.

Effect of central auditory processing disorders on contralateral routing of offside signals (CROS) hearing aids performance

Objectives The aim of this study was to assess central auditory processing (CAP) tests in patients with single sided deafness (SSD)and to study the effect of central auditory processing disorders(CAPD) on the contralateral routing of signal (CROS) hearing aid performance in these subjects. Design This case-control study was performed in Audiovestibular unit, ENT Department. The study included 20 children with SSD and 20 healthy control children. All participants were subjected to CAP tests including pitch pattern sequence (PPS), gap in noise (GIN) and speech intelligibility in noise (SPIN) tests. The child was fitted with CROS and evaluated by SPIN test and bern benefit in single - sided deafness (BBSS) questionnaire. Results There were lower SPIN, PPS, and GIN total correct scores in children with SSD than the control group. The group with normal central test battery has higher SPIN score and significant performance with questionnaire when fitted with CROS. Conclusions Children with normal central auditory processing test battery performed better when fitted with CROS than those with abnormal test battery.

The Prevalence of Hearing Aid Use in Children With Single-Sided Sensorineural Deafness in Oxfordshire

The Prevalence of Hearing Aid Use in Children With Single-Sided Sensorineural Deafness in Oxfordshire

Residual Hearing Does Not Influence the Effectiveness of Beamforming when Using a Cochlear Implant in Conjunction with Contralateral Routing of Signals

Introduction: Contralateral routing of signals (CROS) overcomes the head shadow effect by redirecting speech signals from the contralateral ear to the better-hearing cochlear implant (CI) ear. Here we tested the performance of an adaptive monaural beamformer (MB) and a fixed binaural beamformer (BB) using the CROS system of Advanced Bionics. Methods: In a group of 17 unilateral CI users, we evaluated the benefits of MB and BB for speech recognition by measuring speech reception threshold (SRT) with and without beamforming. MB and BB were additionally evaluated with signal-to-noise ratio (SNR) measurements using a KEMAR manikin. We also assessed the effect of residual hearing in the CROS ear on the benefits of MB and BB. Speech was delivered in front of the listener in a background of homogeneous 8-talker babble noise. Results: With CI-CROS in omnidirectional settings with the T-mic active on the CI as a reference, BB significantly improved SRT by 1.4 dB, whereas MB yielded no significant improvements. The difference in effects on SRT between the two beamformers was, however, not significant. SNR effects were substantially larger, at 2.1 dB for MB and 5.8 dB for BB. CI-CROS with default omnidirectional settings also improved SRT and SNR by 1 dB over CI alone. Residual hearing did not significantly affect beamformer performance. Discussion: We recommend the use of BB over MB for CI-CROS users. Residual hearing in the CROS ear is not a limiting factor for fitting a CROS device, although a bimodal option should be considered.

Effect of Hearing Device Use on Speech-in-Noise Performance in Children with Severe-to-Profound Unilateral Hearing Loss.

Limited evidence exists for the use of rerouting devices in children with severe-to-profound unilateral sensorineural hearing loss. Many laboratory studies to date have evaluated hearing-in-noise performance in specific target-masker spatial configurations within a small group of participants and with only a subset of available hearing devices. In the present study, the efficacy of all major types of nonsurgical devices was evaluated within a larger group of pediatric subjects on a challenging speech-in-noise recognition task. Children (7-18 years) with unaided severe-to-profound unilateral hearing loss (UHL' n = 36) or bilateral normal hearing (NH, n = 36) participated in the present study. The signal-to-noise ratio (SNR) required for 50% speech understanding (SNR-50) was measured using BKB sentences in the presence of proprietary restaurant noise (R-SPACE BSIN-R) in the R-SPACE Sound System. Subjects listened under 2 target/masker spatial configurations. The target signal was directed toward subjects' NH or hearing-impaired ear (45º azimuth), while the interfering restaurant noise masker was presented from the remaining 7 loudspeakers encircling the subject, spaced every 45º. Head position was fixed during testing. The presentation level of target sentences and masking noise varied over time to estimate the SNR-50 (dB). The following devices were tested in all participants with severe-to-profound UHL: air conduction (AC) contralateral routing of signal (CROS), bone conduction (BC) CROS fitted on a headband with and without the use of remote microphone (RM), and an ear-level RM hearing assistance technology (HAT) system. As a group, participants with severe-to-profound UHL performed best when the target signal was directed toward their NH ear. Across listening conditions, there was an average 8.5 dB improvement in SNR-50 by simply orienting the NH ear toward the target signal. When unaided, participants with severe-to-profound UHL performed as well as participants with NH when the target signal was directed toward the NH ear. Performance was negatively affected by AC CROS when the target signal was directed toward the NH ear, whereas no statistically significant change in performance was observed when using BC CROS. When the target signal was directed toward participants' hearing-impaired ear, all tested devices improved SNR-50 compared with the unaided condition, with small improvements (1-2 dB) observed with CROS devices and the largest improvement (9 dB) gained with the personal ear-level RM HAT system. No added benefit nor decrement was observed when RM was added to BC CROS using a 50/50 mixing ratio when the target was directed toward the impaired ear. In a challenging listening environment with diffuse restaurant noise, SNR-50 was most improved in the study sample when using a personal ear-level RM HAT system. Although tested rerouting devices offered measurable improvement in performance (1-2 dB in SNR-50) when the target was directed to the impaired ear, benefit may be offset by a detriment in performance in the opposing condition. Findings continue to support use of RM HAT for children with severe-to-profound UHL in adverse listening environments, when there is one primary talker of interest, to ensure advantageous SNRs.

Objective Comparison of Benefits Derived From Contralateral Routing of Signal Hearing Aid and Bone Conduction Device in Noisy Surroundings in Patients With Single-Sided Deafness.

Single-sided deafness (SSD) leads to non-participation of the diseased ear in generating adequate auditory input, which results in poor speech discrimination in noisy surroundings. The present study objectively compared the audiological benefits rendered by contralateral routing of signal (CROS) hearing aid and bone conduction device (BCD) in patients with SSD >70 dB HL using the modified hearing in noise test (HINT). Patients with SSD >70 dB HL in poor and clinically normal hearing in the better ear were enrolled. Patients aged <18 or >70 years, with a history of neurological insult or ear infection in the last 3 months, mental retardation, psychiatric or developmental disorders, and diabetes were excluded. Modified HINT was performed with the affected ear unaided, aided with CROS hearing aid, and with BCD, generating three groups. Noise signal was presented at a fixed intensity of 65 dB at the neutral position in the center and speech signal was presented to either ear sequentially. The test was repeated with the speech signal fixed at the neutral position and the noise signal presented to either ear. BCD led to a better signal-to-noise ratio (SNR) than CROS hearing aid in all situations except when noise was centralized and speech was presented to the affected ear. A benefit was observed when auditory rehabilitation was used for the affected ear as demonstrated by better SNR scores. The results showed that BCD performed better than CROS hearing aid.

A New Active Osseointegrated Implant System in Patients with Single-Sided Deafness

Objective: The Cochlear™ Osia® System (Osia) is an active transcutaneous bone conduction implant system intended for patients with conductive and mixed hearing loss but can also be used in cases of single-sided deafness (SSD) for the contralateral routing of signal (CROS). The Osia implant is placed subcutaneously under the intact skin behind the ear with the piezoelectric actuator connected to an osseointegrated BI300 implant – a titanium screw used for a 2-stage Baha surgery – on the mastoid. The external processor is magnetically attached to the subcutaneous implant receiver coil. As the Osia has recently been CE certified and is new on the market, with limited patient outcome data for SSD available, the objective of this study was the evaluation of surgical procedure, audiological results, and patient satisfaction for the Osia in SSD patients. Study Design: In a prospective, monocentric clinical observation study, 6 patients (18 years of age or older) with SSD and bone conduction thresholds pure tone average 0.5, 1, 2, and 4 kHz ≤25 dB HL on the contralateral side were implanted with an Osia. Analysis of clinical outcome data with respect to surgical technique, adverse events, audiological measurement, and subjective benefit for SSD patients was conducted. Audiological measurements performed included hearing thresholds, sound field thresholds, word recognition scores (WRS; in %) in quiet, and speech recognition thresholds in noise (in dB SNR). All tests were performed unaided and aided with the Osia. The subjective benefit with the Osia was determined by using 2 questionnaires; the Abbreviated Profile of Hearing Aid Benefit (APHAB) and the Bern Benefit in Single-Sided Deafness (BBSSD). Results: Preliminary results indicate a straightforward surgical procedure with a low rate of complications and an improvement in speech perception in quiet, listening performance in everyday situations and patient satisfaction. However, in one of 6 subjects, a revision surgery had to be performed. Conclusion: Provided that SSD patients are open for CROS hearing, they can benefit from the Osia by reduced head shadow effects and better speech recognition. Special caution should be given to the skin at the site of implantation to avoid complications.

Residual Hearing Affects Contralateral Routing of Signals in Cochlear Implant Users

Introduction: Contralateral routing of signals (CROS) can be used to eliminate the head shadow effect. In unilateral cochlear implant (CI) users, CROS can be achieved with placement of a microphone on the contralateral ear, with the signal streamed to the CI ear. CROS was originally developed for unilateral CI users without any residual hearing in the nonimplanted ear. However, the criteria for implantation are becoming progressively looser, and the nonimplanted ear can have substantial residual hearing. In this study, we assessed how residual hearing in the contralateral ear influences CROS effectiveness in unilateral CI users. Methods: In a group of unilateral CI users (N = 17) with varying amounts of residual hearing, we deployed free-field speech tests to determine the effects of CROS on the speech reception threshold (SRT) in amplitude-modulated noise. We compared 2 spatial configurations: (1) speech presented to the CROS ear and noise to the CI ear (S_CROSN_CI) and (2) the reverse (S_CIN_CROS). Results: Compared with the use of CI only, CROS improved the SRT by 6.4 dB on average in the S_CROSN_CI configuration. In the S_CIN_CROS configuration, however, CROS deteriorated the SRT by 8.4 dB. The benefit and disadvantage of CROS both decreased significantly with the amount of residual hearing. Conclusion: CROS users need careful instructions about the potential disadvantage when listening in conditions where the CROS ear mainly receives noise, especially if they have residual hearing in the contralateral ear. The CROS device should be turned off when it is on the noise side (S_CIN_CROS). CI users with residual hearing in the CROS ear also should understand that contralateral amplification (i.e., a bimodal hearing solution) will yield better results than a CROS device. Unilateral CI users with no functional contralateral hearing should be considered the primary target population for a CROS device.

Clinical and functional results after implantation of the bonebridge, a semi-implantable, active transcutaneous bone conduction device, in children and adults

PurposeAim of the study was to evaluate the surgical, clinical and audiological outcome of 32 implantations of the Bonebridge, a semi-implantable transcutaneous active bone conduction implant.MethodsIn a retrospective cohort study, we analyzed data for 32 implantations in 31 patients (one bilateral case; seven age < 16 years) with conductive or mixed hearing loss, malformations, after multiple ear surgery, or with single-sided deafness as contralateral routing of signal (CROS).ResultsFour implantations were done as CROS. Five cases were simultaneously planned with ear prosthesis anchors, and 23 implantations (72%) were planned through three-dimensional (3D) “virtual surgery.” In all 3D-planned cases, the implant could be placed as expected. For implant-related complications, rates were 12.5% for minor and 3.1% for major complications. Implantation significantly improved mean sound field thresholds from a preoperative 60 dB HL (SD 12) to 33 dB HL (SD 6) at 3 postoperative months and 34 dB HL (SD 6) at > 11 postoperative months (p < 0.0001). Word recognition score in quiet at 65 dB SPL improved from 11% (SD 20) preoperatively to 74% (SD 19) at 3 months and 83% (SD 15) at > 11 months (p < 0.0001). The speech reception threshold in noise improved from − 1.01 dB unaided to − 2.69 dB best-aided (p = 0.0018).ConclusionWe found a clinically relevant audiological benefit with Bonebridge. To overcome anatomical challenges, we recommend preoperative 3D planning in small and hypoplastic mastoids, children, ear malformation, and simultaneous implantation of ear prosthesis anchors and after multiple ear surgery.

Using a cochlear implant processor as contralateral routing of signals device in unilateral cochlear implant recipients

PurposeIn unilateral cochlear implant (CI) recipients, a contralateral routing of signals (CROS) device enables to receive auditory information from the unaided side. This study investigates the feasibility as well as subjective and objective benefits of using a CI processor as a CROS device in unilateral CI recipients.MethodsThis is a single-center, prospective cohort study. First, we tested the directionality of the CROS processor in an acoustic chamber. Second, we examined the difference of speech perception in quiet and in noise in ten unilateral CI recipients with and without the CROS processor. Third, subjective ratings with the CROS processor were evaluated according to the Client Oriented Scale of Improvement Questionnaire.ResultsThere was a time delay between the two devices of 3 ms. Connection of the CROS processor led to a summation effect of 3 dB as well as a more constant amplification along all azimuths. Speech perception in quiet showed an increased word recognition score at 50 dB (mean improvement 7%). In noise, the head shadow effect could be mitigated with significant gain in speech perception (mean improvement 8.4 dB). This advantage was reversed in unfavorable listening situations, where the CROS device considerably amplified the noise (mean: – 4.8 dB). Subjectively, patients who did not normally wear a hearing aid on the non-CI side were satisfied with the CROS device.ConclusionsThe connection and synchronization of a CI processor as a CROS device is technically feasible and the signal processing strategies of the device can be exploited. In contra-laterally unaided patients, a subjective benefit can be achieved when wearing the CROS processor.

Bone-anchored hearing system, contralateral routing of signals hearing aid or cochlear implant: what is best in single-sided deafness?

PurposeThe aim of the study was to compare long-term results after 1 year in patients with single-sided deafness (SSD) who were fitted with different hearing aids. The participants tested contralateral routing of signals (CROS) hearing aids and bone-anchored hearing systems (BAHS). They were also informed about the possibility of a cochlear implant (CI) and chose one of the three devices. We also investigated which factors influenced the choice of device.MethodsProspective study with 89 SSD participants who were divided into three groups by choosing BAHS, CROS, or CI. All participants received test batteries with both objective hearing tests (speech perception in noise and sound localisation) and subjective questionnaires.Results16 participants opted for BAHS-, 13 for CROS- and 30 for CI-treatment. The greater the subjective impairment caused by SSD, the more likely patients were to opt for surgical treatment (BAHS or CI). The best results in terms of speech perception in noise (especially when sound reaches the deaf ear and noise the hearing ear), sound localization, and subjective results were achieved with CI.ConclusionThe best results regarding the therapy of SSD are achieved with a CI, followed by BAHS. This was evident both in objective tests and in the subjective questionnaires. Nevertheless, an individual decision is required in each case as to which SSD therapy option is best for the patient. Above all, the patient's subjective impairment and expectations should be included in the decision-making process.

Listening Effort in School-Aged Children With Limited Useable Hearing Unilaterally: Examining the Effects of a Personal, Digital Remote Microphone System and a Contralateral Routing of Signal System.

Technology options for children with limited hearing unilaterally that improve the signal-to-noise ratio are expected to improve speech recognition and also reduce listening effort in challenging listening situations, although previous studies have not confirmed this. Employing behavioral and subjective indices of listening effort, this study aimed to evaluate the effects of two intervention options, remote microphone system (RMS) and contralateral routing of signal (CROS) system, in school-aged children with limited hearing unilaterally. Nineteen children (aged 7–12 years) with limited hearing unilaterally completed a digit triplet recognition task in three loudspeaker conditions: midline, monaural direct, and monaural indirect with three intervention options: unaided, RMS, and CROS system. Verbal response times were interpreted as a behavioral measure of listening effort. Participants provided subjective ratings immediately following behavioral measures. The RMS significantly improved digit triplet recognition across loudspeaker conditions and reduced verbal response times in the midline and indirect conditions. The CROS system improved speech recognition and listening effort only in the indirect condition. Subjective ratings analyses revealed that significantly more participants indicated that the remote microphone made it easier for them to listen and to stay motivated. Behavioral and subjective indices of listening effort indicated that an RMS provided the most consistent benefit for speech recognition and listening effort for children with limited unilateral hearing. RMSs could therefore be a beneficial technology option in classrooms for children with limited hearing unilaterally.

Hearing Status and Aural Rehabilitative Profile of 878 Patients With Sporadic Vestibular Schwannoma.

To examine the hearing status and aural rehabilitative profile in a national cohort of patients with sporadic vestibular schwannoma (VS). Cross-sectional survey METHODS: A cross-sectional survey of Acoustic Neuroma Association members diagnosed with sporadic VS was performed from February 2017 through January 2019. Self-reported results were used to determine the aural rehabilitative profile of respondents. Among survey respondents, 62.2% (546/878) were not using any hearing-assistive device at time of survey. For the 37.8% (332/878) that were utilizing hearing-assistive devices, 32.8% (109/332) reported using a behind-the-ear hearing aid, 23.8% (79/332) used a contralateral routing of signal (CROS) hearing aid, and 21.7% (72/332) used a bone conduction device. Notably, 41.9% (278/663) of patients who previously underwent tumor treatment reported utilizing a hearing rehabilitation device at some point during VS management compared to 27.0% (58/215) of those undergoing observation with serial imaging (P < .001). Of 275 patients with functional hearing in the ipsilateral ear, 26.5% (73/275) reported having used at least one type of hearing device; 24.0% (66/275) reported use of a conventional hearing aid, 0.7% (2/275) a CROS aid, and 0.4% (1/275) a bone conduction device. Among respondents reporting ipsilateral nonfunctional hearing, 44.9% (258/575) reported having used at least one type of hearing device; 13.0% (75/575) a CROS aid, and 12.3% (71/575) a bone conduction device. Even among a cohort with presumably elevated literacy surrounding hearing rehabilitation options, few patients with a history of unilateral vestibular schwannoma ultimately use hearing assistive devices long-term, suggesting that most patients sufficiently adjust to unilateral hearing loss or are unsatisfied with the benefits achieved with current device options. 4 Laryngoscope, 131:1378-1381, 2021.

Application of Wireless Contralateral Routing of Signal (CROS) Technology in Unilateral Cochlear Implant Users

IntrodutionSingle cochlear implantation usually provides substantial speech intelligibility benefits but bilaterally deaf, unilaterally implanted subjects will continue to experience limitations due to the head shadow effect, like single-sided deaf individuals. In the treatment of individuals with single-sided deafness one option is contralateral routing of signal (CROS) devices, which constitute a non-surgical intervention of the second ear in unilaterally implanted individuals. MethodTwelve experienced adult cochlear implant (CI) users with Naída Q70 processor and the CROS device used in combination participated in the study. For the study three conditions were provided: CI only, omnidirectional microphone mode (CROS deactivated); CI plus CROS activated, omnidirectional microphone mode and CI plus CROS activated, UltraZoom mode. Speech reception thresholds were determined in quiet and noise. Subjective feedback regarding the practical usability of the CROS device and the perceived benefit were collected. ResultsThere was a 27.6% improvement in speech understanding in quiet and 32.5% improvement in noise when CROS device was activated. Using advanced directional microphones, a statistically significant benefit of 35% was obtained. The responses to the questionnaires revealed that the subjects perceived benefit in their everyday lives when using the CROS device with their CI. ConclusionThe investigated CROS device used by unilateral CI recipients in cases where bilateral implantation is not an option provides both subjective and objective speech recognition benefit when the signal is directed to the CROS device. Unfavourable conditions where speech is presented from the CI side and noise from the CROS side or diffusely were not included in this evaluation since the CROS device adds additional noise and performance is expected to decrease as has previously been shown.