Contralateral Routing Of Signal Device Research Articles

CROS or hearing aid? Selecting the ideal solution for unilateral CI patients with limited aidable hearing in the contralateral ear.

A hearing aid or a contralateral routing of signal device are options for unilateral cochlear implant listeners with limited hearing in the unimplanted ear; however, it is uncertain which device provides greater benefit beyond unilateral listening alone. Eighteen unilateral cochlear implant listeners participated in this prospective, within-participants, repeated measures study. Participants were tested with the cochlear implant alone, cochlear implant + hearing aid, and cochlear implant + contralateral routing of signal device configurations with a one-month take-home period between each in-person visit. Audiograms, speech perception in noise, and lateralization were evaluated. Subjective feedback was obtained via questionnaires. Marked improvement in speech in noise and non-implanted ear lateralization accuracy were observed with the addition of a contralateral hearing aid. There were no significant differences in speech recognition between listening configurations. However, the chronic device use questionnaires and the final device selection showed a clear preference for the hearing aid in spatial awareness and communication domains. Individuals with limited hearing in their unimplanted ears demonstrate significant improvement with the addition of a contralateral device. Subjective questionnaires somewhat contrast with clinic-based outcome measures, highlighting the delicate decision-making process involved in clinically advising one device or another to maximize communication benefits.

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.

Contralateral Routing of Signal Disrupts Monaural Sound Localization.

In the absence of binaural hearing, individuals with single-sided deafness can adapt to use monaural level and spectral cues to improve their spatial hearing abilities. Contralateral routing of signal is the most common form of rehabilitation for individuals with single-sided deafness. However, little is known about how these devices affect monaural localization cues, which single-sided deafness listeners may become reliant on. This study aimed to investigate the effects of contralateral routing of signal hearing aids on localization performance in azimuth and elevation under monaural listening conditions. Localization was assessed in 10 normal hearing adults under three listening conditions: (1) normal hearing (NH), (2) unilateral plug (NH-plug), and (3) unilateral plug and CROS aided (NH-plug + CROS). Monaural hearing simulation was achieved by plugging the ear with E-A-Rsoft™ FX™ foam earplugs. Stimuli consisted of 150 ms high-pass noise bursts (3-20 kHz), presented in a random order from fifty locations spanning ±70° in the horizontal and ±30° in the vertical plane at 45, 55, and 65 dBA. In the unilateral plugged listening condition, participants demonstrated good localization in elevation and a response bias in azimuth for signals directed at the open ear. A significant decrease in performance in elevation occurs with the contralateral routing of signal hearing device on, evidenced by significant reductions in response gain and low r2 value. Additionally, performance in azimuth is further reduced for contralateral routing of signal aided localization compared to the simulated unilateral hearing loss condition. Use of the contralateral routing of signal device also results in a reduction in promptness of the listener response and an increase in response variability. Results suggest contralateral routing of signal hearing aids disrupt monaural spectral and level cues, which leads to detriments in localization performance in both the horizontal and vertical dimensions. Increased reaction time and increasing variability in responses suggests localization is more effortful when wearing the contralateral rerouting of signal device.

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.

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.

Aplicación de la tecnología de enrutamiento inalámbrico contralateral de la señal (CROS) en usuarios de implante coclear unilateral

IntroductionSingle 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 users with Naída Q70 processor and the CROS device used in combination participated in the study. For the study 3 conditions were provided: cochlear implant only, omnidirectional microphone mode (CROS deactivated); cochlear implant plus CROS activated, omnidirectional microphone mode and cochlear implant 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 cochlear implants. 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 cochlear implant 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.

Application of Wireless Contralateral Routing of Signal Technology in Unilateral Cochlear Implant Users with Bilateral Profound Hearing Loss.

The aim of the study was to determine if contralateral routing of signal (CROS) technology results in improved hearing outcomes in unilateral cochlear implant (CI) patients and provides similar gains in speech perception in noise to traditional monaural listeners (MLs). The study is a prospective, within-subject repeated-measures experiment. Adult, English-speaking patients with bilateral severe-profound sensorineural hearing loss using an Advanced Bionics CI (n = 12) in one ear were enrolled for the study. Hearing performance in the monaural listening condition (CI only) was compared with the CROS-aided (unilateral CI + CROS) condition. Participants were tested for speech-in-noise performance using the Bamford-Kowal-Bench Speech-in-Noise™ test materials in the speech front/noise front (0 degrees/0 degrees azimuth), speech front/noise back (0 degrees/180 degrees azimuth), speech deaf ear/noise monaural ear (90 degrees/270 degrees azimuth), and speech monaural ear/noise deaf ear (90 degrees/270 degrees azimuth) configurations. Localization error was assessed using three custom stimuli consisting of 1/3 octave narrowband noises centered at 500 and 4000 Hz and a broadband speech stimulus. Localization stimuli were presented at random in the front hemifield by 19 speakers spatially separated by 10 degrees. Outcomes were compared with a previously described group of traditional MLs in the CROS-aided condition (normal hearing ear + CROS). All participants were tested acutely with no adaptation to the CROS device. Statistical analyses were performed using Wilcoxon signed rank tests for nonparametric data and paired sample. Statistical significance was set to p < 0.00625 after Bonferroni adjustment for eight tests. Significant benefit was observed from unaided to the CI + CROS-aided condition for listening in noise across most listening conditions with the greatest benefit observed in the speech deaf ear/noise monaural ear (90 degrees/270 degrees azimuth) condition (p < 0.0005). When compared with traditional MLs, no significant difference in decibel gain from the unaided to CROS-aided conditions was observed between participant groups. There was no improvement in localization ability in the CROS-aided condition for either participant group and no significant difference in performance between traditional MLs and unilateral CI listeners. These findings support that unilateral CI users are capable of achieving similar gains in speech perception to that of traditional MLs with wireless CROS. These results indicate that the use of wireless CROS stimulation in unilateral CI recipients provides increased benefit and an additional rehabilitative option for this population when bilateral implantation is not possible. The results suggest that noninvasive CROS solutions can successfully rehabilitate certain monaural listening deficits, provide improved hearing outcomes, and expand the reach of treatment in this population.

Benefits of a contralateral routing of signal device for unilateral Naída CI cochlear implant recipients.

Many bilaterally deaf adults are only able to receive one cochlear implant (CI), resulting in suboptimal listening performance, especially in challenging listening environments. Adding a contralateral routing of signal (CROS) device to a unilateral CI is one possibility to alleviate these challenges. This study examined the benefit of such a CROS device. Thirteen adult subjects with at least 6months of CI use, and no or limited benefit of a hearing instrument in the contralateral ear were included in the study. The perceived benefit of a CROS device in everyday listening environments was evaluated up to 1 year after initial fitting using several questionnaires. Speech intelligibility performance was determined using the French matrix sentence test in quiet and in two speech-in-noise setups and was followed for 3 months after CROS fitting. Subjects indicated high satisfaction with the practical usability of the CROS device and long-term device retention was high. Perceived benefits in everyday listening environments were reported. Formal speech intelligibility tests revealed statistically significant median improvements of 6.93dB SPL (Wilcoxon Z = 2.380, p = 0.017) in quiet and up to 8.00dB SNR (Wilcoxon Z = 2.366, p = 0.018) in noise. These benefits were accessible immediately without a need for prolonged acclimatization. Subjective satisfaction and device retention as well as speech intelligibility benefits in quiet and in noise prove the CROS device to be a valuable addition to a unilateral CI in cases of bilateral deafness where bilateral implantation is not an option.

Evaluation of a wireless contralateral routing of signal (CROS) device with the Advanced Bionics Naída CI Q90 sound processor

Objectives: Cochlear implants (CIs) usually provide severe to profoundly deaf recipients with speech intelligibility in quiet. In difficult listening situations such as background noise however, communication often remains challenging. For unilateral CI recipients with a bilateral hearing loss, speech intelligibility for speech sources on the non-implanted side is further impaired by the head-shadow effect. One possibility to overcome this impairment is the use of Contralateral Routing of Signal (CROS) systems, which capture sounds from the non-implanted side and (wirelessly) transmit them to the implant processor, therefore increasing audibility. Such a CROS system was evaluated in this study.Methods: Speech intelligibility in noise was measured in several spatial listening setups using the Oldenburg matrix sentence test in ten cochlear implant users. Performance was compared between listening with the CI alone and listening with the CI in combination with a wireless CROS device. Following an extended trial phase, subjective feedback regarding the device benefit in everyday life was collected via the Bern Benefit in Single Sided Deafness (BBSS) questionnaire.Results: The addition of the wireless CROS device significantly improved speech intelligibility by 7.2 dB (median) in spatial noise. Using advanced directional microphones, a statistically significant benefit of 4.4 dB (median) could be shown in a diffuse noise field. Responses to the BBSS questionnaire revealed that subjects perceived benefit in their everyday lives when using the CROS device with their CI.Conclusion: The investigated CROS system presents a valuable addition to a unilateral CI in cases where bilateral implantation is not an option.

Nonsurgical Management of Single-Sided Deafness: Contralateral Routing of Signal.

In recent years, an increasing research effort has been directed toward remediation of single-sided deafness. Contralateral routing of signal (CROS) is the longest standing rehabilitation solution for individuals with single-sided deafness. The primary goal of CROS technology is to transfer the signal received at the deaf ear to the better hearing ear, thereby reducing the impact of the acoustic head-shadow. This allows for individuals with single-sided deafness to regain access to sounds located at the deaf ear. The hearing deficits associated with single-sided deafness are often debilitating. While surgical management of single-sided deafness is on the rise, CROS hearing aids offer a nonsurgical option to compensate for some of the deficits that occur when a listener is limited to a single ear. Limitations of early CROS devices resulted in poor adoption and acceptance in those with single-sided deafness. Following significant advances in both design and technology, the acceptance of CROS devices has increased in recent years. This paper reviews relevant literature in CROS application for the management of single-sided deafness. Technological advances, benefits, limitations, and clinical considerations are also reviewed in this article.

Contralateral Routing of Signal Yields Significant Speech in Noise Benefit for Unilateral Cochlear Implant Recipients.

Bilateral cochlear implantation is the standard of care for individuals with moderate sloping-to-profound sensorineural hearing loss who do not receive benefit from appropriately fit hearing aids. Because of financial, insurance, or medical reasons, some unilateral cochlear implant (CI) recipients are unable to obtain a second CI. Here, we evaluated the first clinically available solution for individuals who have been unilaterally implanted and who do not or cannot use technology (e.g., hearing aid or CI) on the non-implanted ear. We aimed to investigate how the addition of a contralateral routing of signal (CROS) device could provide objective and/or subjective benefit to adult CI recipients with moderate-to-profound hearing loss in the non-implanted ear. Single-center prospective study using a within-subjects repeated-measures design. Participants included ten experienced unilateral CI recipients with severe-to-profound (n = 9) or moderate-to-profound (n = 1) sensorineural hearing loss in the non-implanted ear. At the time of study enrollment, participants did not use any technology on the non-implanted ear. No other exclusion criteria were used. Individuals were tested with and without a CROS device worn on the non-implanted ear. We obtained measures of speech understanding in quiet (50 and 65 dBA) and in noise (+5-dB signal-to-noise ratio with a 65-dBA speech signal) both with and without the CROS device in an acute listening condition. Subjective benefit was assessed via the Speech, Spatial and Qualities 12-item questionnaire before CROS fitting and after two weeks of continuous use. A mixed-model, repeated-measures analysis of variance was completed with three talker locations and three presentation levels included as within-subjects factors and the presence or absence of a CROS device as a between-subjects factor. There was an 11% improvement in speech understanding in noise with the addition of the CROS device when speech was located at 0° azimuth. Subjective benefit in the speech domain of the SSQ was also observed. Use of CROS provided both subjective and objective speech recognition benefit for unilateral CI recipients who do not have access to bilateral cochlear implantation.

Hearing devices for children with unilateral hearing loss: Patient- and parent-reported perspectives

ObjectiveManagement of children with unilateral hearing loss is not standardized. The primary goal of this study was to elicit patient- and parent-reported perspectives regarding usage of hearing devices in pediatric UHL and to suggest a basic algorithmic approach to management. MethodsOur tertiary care center recruited families of youth ages 5–19 years with unilateral hearing loss from January 2014 through October 2015. Parents of all youths completed a 36-item survey, and some youth ages 11–19 years participated in hour-long interviews. We assessed patterns of hearing device usage among participants, and performed qualitative data analysis to understand factors considered by youths when deciding whether or not to use a hearing device. ResultsSurvey information was collected for 50 patients. Distribution of hearing loss severity in affected ear was mild 14%, moderate 26%, severe 22%, and profound 38%. The majority of children had sensorineural hearing loss (57%), followed by mixed (32%), and then conductive (11%). 34 children (68%) had tried a hearing device; 20 continued to use the device. Retention rates were similar among children with different degrees of hearing loss: mild 66%, moderate 50%, severe 60%, profound 64%. Sixteen children tried a wireless contralateral routing of signal (CROS) device, and 15 tried a behind-the-ear (BTE) hearing aid. Retention rates for CROS and BTE devices were 69% and 47%, respectively. The most common reason for cessation of use was discomfort, followed by lack of benefit. ConclusionA majority of children with unilateral hearing loss who tried a hearing device continued to use it, and retention rates were similar across all degrees of hearing loss. These findings suggest that personal hearing devices should be included in management protocols.

Benefit of a Contralateral Routing of Signal Device for Unilateral Cochlear Implant Users

Objective: To investigate objective and subjective effects of an adjunctive contralateral routing of signal (CROS) device at the untreated ear in patients with a unilateral cochlear implant (CI). Design: Prospective study of 10 adult experienced unilateral CI users with bilateral severe-to-profound hearing loss. Speech in noise reception (SNR) and sound localization were measured with and without the additional CROS device. SNR was measured by applying speech signals at the untreated/CROS side while noise signals came from the front (S90N0). For S0N90, signal sources were switched. Sound localization was measured in a 12-loudspeaker full circle setup. To evaluate the subjective benefit, patients tried the device for 2 weeks at home, then filled out the abbreviated Speech, Spatial and Qualities of Hearing Scale as well as the Bern benefit in single-sided deafness questionnaires. Results: In the setting S90N0, all patients showed a highly significant SNR improvement when wearing the additional CROS device (mean 6.4 dB, p < 0.001). In the unfavorable setting S0N90, only a minor deterioration of speech understanding was noted (mean -0.66 dB, p = 0.54). Sound localization did not improve substantially with CROS. In the two questionnaires, 12 of 14 items showed an improvement in mean values, but none of them was statistically significant. Conclusion: Patients with unilateral CI benefit from a contralateral CROS device, particularly in a noisy environment, when speech comes from the CROS ear side. © 2014 S. Karger AG, Basel

Subjective and Objective Outcomes from New BiCROS Technology in a Veteran Sample

Patients with single-sided deafness (SSD), where one ear has an unaidable hearing loss and the other ear has normal or aidable hearing, often complain of difficulties understanding speech and localizing sound sources, and report a higher self-perceived hearing disability. Patients with SSD may benefit from using contralateral routing of signal (CROS) or bilateral contralateral routing of the signal (BiCROS) amplification. Dissatisfaction of previously available (Bi)CROS devices has been reported, such as, interfering transmissions, low-fidelity sound quality, poor "user-friendly" set-up, and a bulky and cosmetically cumbersome appearance. Recent advances in hearing aid technology have improved (Bi)CROS hearing aids; however, these devices have not been experimentally evaluated. We hypothesized that newer technology with reports of improved digital signal processing, wireless transmission, and physical design would be as good, or better than, our participants' previous-generation BiCROS systems. A within-subjects, pretest-posttest design was executed. Thirty-nine veterans (one female, 38 males; mean age = 74 yr, range = 49-85 yr) from the Audiology Section of the Bay Pines Veterans Affair Healthcare System participated. All participants were previously experienced BiCROS hearing aid users with varying degrees of sensorinerual hearing impairment in their better ear. Participants were provided at least 4 wk of consistent use with the new BiCROS. DATA COLLECTION AND ANALYSES: Participants completed three research visits. At Visit 1, with their previous BiCROS, and at Visit 3, with their new BiCROS, the following objective and subjective measures were obtained: (1) soundfield speech-in-noise testing using the Words-In-Noise (WIN) test; (2) speech, spatial, and qualities of the hearing scale (SSQ) questionnaire; (3) selected questions from the MarkeTrak questionnaire; and, (4) three open-ended questions. Data were analyzed using parametric and nonparametric statistics. Overall, the objective (WIN) and subjective (SSQ, MarkeTrak, and open-ended questions) measures indicated that the new BiCROS provided better outcomes than the previous BiCROS system. In addition, an overlap of favorable results was seen across measures. Of the 39 participants, 95% reported improvements with the new BiCROS and chose to utilize the device regularly. The favorable objective and subjective outcomes indicate that the new BiCROS system is as good, or better than, what was previously utilized by our sample of veterans.

Assessment of Patient Satisfaction with Various Configurations of Digital CROS and BiCROS Hearing Aids

We conducted a study of 91 patients with severe-to-profound asymmetric hearing loss to assess their satisfaction with digital contralateral routing of signal (CROS) or bilateral contralateral routing of signal (BiCROS) hearing aids, Satisfaction was evaluated on the basis of the number of patients who elected to purchase their hearing aid following a free 30-day trial and on the results of a subsequent 8-question survey. We found that overall patient satisfaction was generally high. At the end of the 30-day trial, 66 of the 91 patients (72.5%) elected to keep their CROS or BiCROS device, a percentage that is far greater than the acceptance rates of 10 to 20% that had been previously reported with older models of the CROS and BiCROS devices. According to the survey responses, those who kept their devices gave them an overall rating of 3.4 on a scale of 1 (very dissatisfied) to 5 (very satisfied); those who returned their devices gave them an overall rating of 1.9.

Transcranial contralateral cochlear stimulation in unilateral deafness

Objectives The purpose of this study is to evaluate the effectiveness of Bone Anchored Cochlear Stimulator (BAHA) in transcranial routing of signal by implanting the deaf ear. Study design and settings Eighteen patients with unilateral deafness were included in a multisite study. They had a 1-month pre-implantation trial with a contralateral routing of signal (CROS) hearing aid. Their performance with BAHA was compared with the CROS device using speech reception thresholds, speech recognition performance in noise, and the Abbreviated Profile Hearing Benefit and Single Sided Deafness questionnaires. Results Patients reported a significant improvement in speech intelligibility in noise and greater benefit from BAHA compared with CROS hearing aids. Patients were satisfied with the device and its impact on their quality of life. No major complications were reported. Conclusion and significance BAHA is effective in unilateral deafness. Auditory stimuli from the deaf side can be transmitted to the good ear, avoiding the limitations inherent in CROS amplification.