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

PURPOSE: The 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. METHODS: Prospective 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. RESULTS: 16 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. CONCLUSION: The 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.

Is the cochlear implant a successful long-term solution for single-sided deaf and asymmetric hearing-impaired patients?

PURPOSE: We investigated the long-term results of cochlear implant (CI) recipients with asymmetric hearing loss (AHL) or single-sided deafness (SSD). We focused on wearing behavior, audiometric hearing rehabilitation, and subjective benefits of the CI. CI is expected to improve audiological results, subjective hearing perception, and tinnitus burden. METHODS: Speech recognition in background noise and sound localization were assessed preoperatively and after at least six years of CI experience. Validated questionnaires determined the subjective benefit of CI use and the subjective evaluation of tinnitus. RESULTS: Over 80% of the included AHL and SSD CI recipients used their CI between 6 and 10 h daily; four subjects with SSD were non-users. Speech recognition in background noise and sound localization improved significantly compared with the unaided preoperative situation. Additionally, CI improved subjective speech intelligibility and spatial hearing impression while reducing tinnitus burden. CONCLUSION: Subjects with AHL and SSD benefit from CI, subjectively and audiologically. Cochlear implant is a successful long-term treatment for AHL and SSD.

Comparison of Speech Recognition and Localization Ability in Single-sided Deaf Patients Implanted With Different Cochlear Implant Electrode Array Designs.

OBJECTIVE: Choice of electrode array (EA) design and differences in outcome are major concerns both to patients with single-sided deafness (SSD) and to surgeons before cochlear implant (CI) surgery. The present work investigates the effects of EA design on 1) insertion depths, and 2) audiological outcomes of SSD CI recipients. STUDY DESIGN: Retrospective study. SETTING: Tertiary academic center. PATIENTS: Forty patients with acquired SSD matched according to duration of deafness MAIN OUTCOME MEASURES:: Fourteen CI recipients were implanted with a perimodiolar electrode (cochlear perimodiolar [CPM]), 12 with a shorter lateral wall electrode (cochlear lateral wall [CLW]), and 14 with a longer lateral wall electrode array (medEl lateral wall [MLW]). Postoperative rotational tomography was evaluated to determine cochlear size and EA angle of insertion depth (AID). Binaural speech comprehension in noise (in three configuration presentations) and localization ability were assessed 12 months postoperatively with CI. RESULTS: AID was significantly deeper in MLW (mean 527.94 degrees) compared with the CPM (mean 366.35 degrees) and CLW groups (mean 367.01 degrees). No significant difference in AID was seen between the CPM and CLW groups (difference 0.66 degrees). Cochlear sizes revealed no significant differences between any groups. All three groups showed significant improvement in head shadow effect (difference on average CPM: 6.3 dB SPL, CLW 5 dB SPL, and MLW 4.05 dB SPL) and localization ability at 12 months postoperatively (difference on average CPM: 19.72 degrees, CLW: 24 degrees, and MLW: 12.9 degrees). No significant difference in the extent of audiological benefit was observed between any groups. CONCLUSION: No effect on binaural benefit was apparent from the selection of the three EA designs in SSD CI recipients. Further studies focusing on subjective results, sound quality, and music perception depending on EA design in SSD CI recipients are needed.

Long-term results of cochlear implantation in children with congenital single-sided deafness.

PURPOSE: The purpose of this retrospective study was to investigate the outcome and critical age of cochlear implantation in congenital single-sided deafness (SSD). METHODS: 11 children with congenital SSD were implanted with a cochlear implant (CI). Auditory performance was measured through the results of speech discrimination, subjective assessment by the Categories of auditory performance (CAP) score, the Speech, Spatial and Qualities scale questionnaire (SSQ) and the German version of the IOI-HA [Internationales Inventar zur Evaluation von Hörgeräten (IIEH, version for CI)]. RESULTS: Long-term follow-up [median: 3 years and 5 months (3;5 years)] revealed that nine children use their CI (> 8 h/day) and two became nonusers. In children aged below 3;2 years at surgery, there was a substantial long-term increase in speech discrimination and subjective benefit. Children over 4;4 years of age at CI surgery improved partially in audiological/subjective measurements. Among children above 5 years, the SSQ score did not improve despite further slight improvement in speech discrimination long-term. CONCLUSION: Our data suggest a critical age for CI surgery below 3 years in children with congenital SSD for successful hearing rehabilitation. It is mandatory to identify children with SSD as early as bilaterally deaf children.

Speech Perception in Quiet and Noise With an Off the Ear CI Processor Enabling Adaptive Microphone Directionality.

OBJECTIVE: To investigate the impact of the wearing position of an off-the-ear-processor (OTE) on speech perception in quiet and noise. PATIENTS: The study group consisted of 16 adult subjects with bilateral severe-to-profound sensorineural hearing loss, 2 of them unilaterally, and 14 bilaterally provided with cochlear implants. MAIN OUTCOME MEASURES: Speech perception in quiet and noise was measured for frontal presentation with the recipients behind-the-ear processor CP810 or CP910 and the OTE processor Kanso (Cochlear Limited, Sydney, Australia). Additionally, speech performance in noise with the OTE for spatially separated signal and noise sources was assessed. RESULTS: The recipients showed monosyllabic word recognition scores in quiet between 65 and 95% and speech reception thresholds in noise between 2.4 and -5.5 dB SNR with the OTE. For frontal presentation of speech and noise, application of the adaptive directional microphone (Beam) yielded a slight median decrement of 0.6 dB for the speech reception threshold compared with standard directionality. However, huge median improvements, ranging from -3.7 to -11.6 dB, for the three tested conditions with spatially separated sources (S0NIL, S0NCL, S0N180) were observed. CONCLUSION: The beamforming algorithm in the investigated OTE processor provides similar benefits as described in previous studies for behind-the-ear processors in conditions with spatially separated speech and noise sources. Adaptive microphone directionality can be successfully implemented in an OTE processor. The OTE processor's potential to increase usability, comfort, and cosmetics might not be compromised by a deterioration of speech performance.

Cochlear Implantation in Children With Congenital Unilateral Deafness: A Case Series.

OBJECTIVES: Cochlear implant is regarded as a treatment option for hearing rehabilitation of adults with unilateral sensorineural hearing loss. A clear benefit has been experienced in regard to speech comprehension in noise, localization, and quality of life. The aim of this study was to investigate the benefit of cochlear implantation for children with congenital unilateral hearing loss. STUDY DESIGN: Retrospective case series. SETTING: Tertiary referral center; cochlear implant program. PATIENTS: Ten children with congenital unilateral hearing loss. INTERVENTION: After extensive consultation with the families and intensive counseling, the children received a cochlear implant. MAIN OUTCOME MEASURES: Categories of auditory performance, speech discrimination in open set, subjective assessment by Speech, Spatial and Qualities scale questionnaire. CONCLUSION: Eight of ten children use their cochlear implant consistently on a daily basis. Two children who were equipped with an implanted device at a later age tend to nonuse of the device. The evaluation of binaural hearing in small children is still difficult and methods have to be developed to allow objective assessment.

Cochlear implantation for hearing rehabilitation in single-sided deafness after translabyrinthine vestibular schwannoma surgery.

The aim of the study was to investigate the option of cochlear implantation (CI) in resultant single-sided deafness associated with unilateral translabyrinthine resection of sporadic vestibular schwannoma (VS). This is a retrospective study performed at Tertiary Care Academic Centre. Following extensive counselling regarding the potential for delayed CI, translabyrinthine VS resection was performed and an intracochlear placeholder was inserted to allow later CI in 11 patients who showed intraoperative microscopic confirmation of preserved cochlear nerve anatomy. Follow-up magnetic resonance imaging (MRI) and promontory testing were performed 1 year after surgery to confirm the absence of VS recurrence and viable cochlea. Confirmed CI candidates underwent a second procedure where the placeholder was removed and the CI inserted (4/11). Preimplant unaided and CI-aided evaluations at 12 and 24 months were performed for subjective and objective hearing outcomes. Tinnitus suppression was also measured for implant on and off effects. Available audiological data for three patients demonstrated significant hearing benefits for 'speech from deaf/implanted side, noise from the normal-hearing side' in all three patients and localisation ability improved for 2/3 patients. Subjective findings presented similar results. For the two patients with preimplant tinnitus, complete suppression occurred during active CI. CI is beneficial for hearing rehabilitation and tinnitus reduction in SSD patients with remaining viable cochlear nerve after translabyrinthine VS surgery. Counselling on the risks of intracochlear placeholder insertion and the inherent limitations for ongoing MRI investigations of VS recurrence is essential.

Electrophysiological Detection of Scalar-Changing Perimodiolar Cochlear Electrode Arrays: A Six-Month Follow-Up Study.

The position of the cochlear electrode array within the scala tympani is essential for optimal hearing benefit. An intraoperative neural response telemetry ratio (NRT ratio; a threshold ratio of pairs of apical and basal electrodes) has been established, which can provide information about the intracochlear electrode array position. Out of a previous collective of 85 patients, the 6-month follow-up electrophysiological NRT data of 37 patients have been included in this study. Comparing the intraoperatively estimated NRT ratio with the 6-month follow-up NRT ratio, it remained unchanged intraindividually in 92% of cases. Within this group the NRT ratio and the intracochlear position of the electrode array matched in all cases. There were two newly occurring mismatches and one new match was observed. After a period of 6 months the NRT ratio remained unchanged in most cases and showed a good correlation with the intracochlear position of the electrode array.

A Comparison of Different Methods to Generate Tooth Surface Models Without Applying Ionizing Radiation for Digital 3-Dimensional Image Fusion With Magnetic Resonance Imaging-Based Data of the Head and Neck Region.

OBJECTIVE: The 3-dimensional display of the vocal tract and teeth is necessary in numerous clinical and scientific contexts. Due to the different tissue properties this can only be achieved by combining different imaging techniques. A comparison of methods to record the tooth surface to create combined models of the vocal tract and teeth without applying ionizing radiation is displayed in this study. METHODS: Four methods to record the tooth surface were compared concerning their clinical accuracy after combination with magnetic resonance imaging (MRI)-based vocal tract models. With 2 of the presented methods the information of the tooth surface was obtained from MRI data. With the other 2 methods, the tooth surface was captured using a digital and a conventional impression technique. RESULTS: Impression techniques received the best rating results. CONCLUSIONS: The digital 3-dimensional image fusion of dental impression and MRI resulted in a virtual model of the vocal tract and teeth with a high clinical accuracy without applying ionizing radiation.

Binaural integration of periodically alternating speech following cochlear implantation in subjects with profound sensorineural unilateral hearing loss.

In cochlear implant (CI) recipients with unilateral hearing loss (UHL) and normal hearing (NH) in the contralateral ear, the central auditory system receives signals of different auditory modalities, i.e. electrically via the CI ear as well as acoustically via the NH ear. The present study investigates binaural integration of bimodal stimulation in the central auditory system of 10 CI subjects with UHL by applying a modified version of the Rapidly Alternating Speech Perception (RASP) test to characterise speech recognition ability under monotic and dichotic listening arrangements. Subsequently, the results for each monotic and dichotic test condition were compared to quantify the binaural benefit from CI usage. The study results demonstrate significantly improved speech recognition under dichotic compared to monotic listening conditions, providing evidence that there is binaural integration of acoustically and electrically transmitted speech segments in the central nervous system at brainstem and cortical levels. In contrast to more commonly used tests of binaural integration, such as localisation, the RASP test provides the clinical option to investigate binaural integration involving structures at the cortical level.

Cochlear implantation in children with single-sided deafness: does aetiology and duration of deafness matter?

For adult patients with single-sided deafness (SSD), treatment with a cochlear implant (CI) is well established as an acceptable and beneficial hearing rehabilitation method administered routinely in clinical practice. In contrast, for children with SSD, CI has been applied less often to date, with the rationale to decide either on a case-by-case basis or under the realm of clinical research. The aim of our clinical study was to evaluate the longitudinal benefits of CI for a group of children diagnosed with SSD and to compare their outcomes with respect to patient characteristics. Evaluating a pool of paediatric SSD patients presenting for possible CI surgery revealed that the primary aetiology of deafness was congenital cochlear nerve deficiency. A subgroup of children meeting the CI candidacy criteria for the affected ear (the majority with acquired hearing loss) were enrolled in the study. Preliminary group results suggest substantial improvements in speech comprehension in noise and in the ability to localise sound, which was demonstrated through objective and subjective assessments after CI treatment for the group, with results varying from patient to patient. Our study shows a trend towards superior outcomes for children with acquired hearing loss and a shorter duration of hearing loss compared to congenitally deafened children who had a longer duration of SSD. This indicates an interactive influence of the age at onset, aetiology and duration of deafness upon the restoration of binaural integration and the overall benefits of sound stimulation to two ears after CI treatment. Continued longitudinal investigation of these children and further studies in larger groups may provide more guidance on the optimal timing of treatment for paediatric patients with acquired and congenital SSD.

Electrophysiological Detection of Intracochlear Scalar Changing Perimodiolar Cochlear Implant Electrodes: A Blinded Study.

OBJECTIVE: To investigate whether a previous established neural response telemetry (NRT) ratio corresponds with the scalar position of the CI electrode. STUDY DESIGN: Retrospective blinded controlled study. SETTING: Tertiary referral center. PATIENTS: The electrophysiological data sets of 85 patients with measured intraoperative NRTs were evaluated. All patients were implanted with the same CI system. Using a flat panel tomography system, the position of the electrode array was confirmed radiologically. INTERVENTIONS: The radiological results were blindly compared with the intraoperatively obtained electrophysiological data (NRT ratio) and statistically evaluated. In a second step, irregularities between the NRT ratios and the radiologically confirmed electrode positions were determined and the entire study material was investigated deeper. MAIN OUTCOME MEASURES: Correlation of the NRT ratio with the intracochlear position of the CI electrode. RESULTS: By electrophysiological evaluation only, 69 patients were detected without a scalar change at first. In 16 patients, a scalar change was probable. A significant correlation between the radiological results and the NRT ratios was found. Secondly, additional patient characteristics were identified which influences the electrode's position. Excluding those patients, the selectivity and specificity of the NRT ratio could be increased to a higher level. CONCLUSION: Evidenced by a blinded group of patients, we are able to show that the electrode array position within the cochlea could be predicted using the NRT ratio.

Radiologic Results and Hearing Preservation With a Straight Narrow Electrode via Round Window Versus Cochleostomy Approach at Initial Activation.

OBJECTIVE: To evaluate the potential influence of two different cochlear implant (CI) electrode carrier approaches to the scala tympani in terms of insertion depth and angle as well as hearing preservation. STUDY DESIGN: Retrospective follow-up study. SETTING: Tertiary care academic center. PATIENTS: Forty-one adult subjects underwent cochlear implantation using the Cochlear Nucleus CI 422 slim straight electrode (Cochlear Limited, New South Wales, Australia) with the intent of achieving atraumatic electrode insertion and hearing preservation. INTERVENTIONS: Fourteen subjects were implanted using a cochleostomy approach and 27 via a round window approach. MAIN OUTCOME MEASURES: Radiologic assessment of insertion depth and angle was performed on postoperative rotational tomography. Postoperative low-frequency hearing preservation, complete loss of residual low-frequency hearing, and speech perception in quiet measures were obtained in defined intervals for both groups. RESULTS: Mean insertion depth reached 21.5 mm (standard deviation, 1.1), whereas mean insertion angle of 388 degrees (standard deviation, 34.7) was revealed for all CI recipients, with no significant difference between the cochleostomy cohort and the round window cohort. The CI-aided speech perception in quiet showed significantly higher scores 3 to 4 months after activation compared with the preoperative speech perception results. The audiologic data demonstrated no statistically significant difference in probability of complete loss of residual low-frequency hearing at initial activation between the cochleostomy group and the round window group. CONCLUSION: The present results suggest that similar insertion depth and angle as well as similar low-frequency hearing preservation can be achieved in cochlear implantation with this straight narrow electrode via either cochleostomy approach or round window approach at least at initial activation. This fact gives the surgeon the opportunity to adapt access to the scala tympani as needed.

Evaluation of the Relationship between the NRT-Ratio, Cochlear Anatomy, and Insertions Depth of Perimodiolar Cochlear Implant Electrodes.

The position of the cochlear implant electrode array within the scala tympani is essential for an optimal postoperative hearing benefit. If the electrode array changes in between the scalae intracochlearly (i.e., from scala tympani to scala vestibuli), a reduced auditory performance can be assumed. We established a neural response telemetry-ratio (NRT-ratio) which corresponds with the scalar position of the electrodes but shows within its limits a variability. The aim of this study was to determine if insertion depth angle or cochlea size influences the NRT-ratio. The intraoperative electrophysiological NRT data of 26 patients were evaluated. Using a flat panel tomography system, the position of the electrode array was evaluated radiologically. The insertion depth angle of the electrode, the cochlea size, and the NRT-ratio were calculated postoperatively. The radiological results were compared with the intraoperatively obtained electrophysiological data (NRT-ratio) and statistically evaluated. In all patients the NRT-ratio, the insertion depth angle, and the cochlea size could be determined. A significant correlation between insertional depth, cochlear size, and the NRT-ratio was not found. The NRT-ratio is a reliable electrophysiological tool to determine the scalar position of a perimodiolar electrode array. The NRT-ratio can be applied independent from insertion depth and cochlear size.

Comparison of 3D C-arm-based registration to conventional pair-point registration regarding navigation accuracy in ENT surgery.

OBJECTIVE: Navigation surgery on the skull base requires high navigation accuracy. The registration process is related to the main loss in accuracy. This study compared titanium screw registration with an inbuilt registration process of a 3-dimensional (3D) C-arm. STUDY DESIGN: Experimental phantom study. SETTING: Operating room. SUBJECTS AND METHODS: Four skull models were fabricated with a 3D printer based on the patient's computed tomography (CT) data sets and fitted with an individually customized silicone skin. A 3D-isocentric C-arm fluoroscopic image intensifier system combined with a flat panel detector performed scans of petrous bones (PB) and paranasal sinuses (PS). The navigation accuracy of pair-point registration (PPR) with titanium screws was compared with C-arm-based registration. RESULTS: Overall navigation accuracy was 1.53 ± 0.51 mm after PPR and 1.26 ± 0.12 mm after C-arm registration (P = .0259). PPR showed the best accuracy results on PS (1.28 ± 0.69 mm), followed by right PB (1.43 ± 0.52 mm) and left PB (1.74 ± 0.69 mm). A significant difference was seen only between PS and left PB (P = .0206). In contrast, C-arm registration revealed significantly lower target registration errors (TREs) on PB (0.99 ± 0.23 mm right PB, P < .0001; 1.2 ± 0.35 mm left PB, P = .0412) compared with PS. When comparing both registration modalities, C-arm registration was significantly superior on PB. With respect to specific anatomic locations, C-arm-based registration showed significantly lower TREs on the frontal and lateral skull base than PPR. CONCLUSION: C-arm-based navigation shows higher navigation accuracy on the skull base compared with PPR. As the 3D C-arm allows real-time imaging and real-time navigation, it will be a helpful tool for skull base surgeons.

The bonebridge as a transcutaneous bone conduction hearing system: preliminary surgical and audiological results in children and adolescents.

The Bonebridge (®) (BB, Med-El) is a newly designed transcutaneous active bone conductive implant with functional outcome similar to percutaneous bone-anchored hearing systems (BAHS). It is currently approved only for patients ≥18 years. Since the BB allows the skin to remain intact and therefore should be able to overcome some of the issues related to percutaneous BAHS including skin reactions, wound infection and implant extrusion, it would be especially attractive for use in children. We present a preliminary series of the first three cases of BB implantation in children/adolescents (10-16 years). Two subjects were affected by conductive hearing loss (CHL) and one subject by single-sided deafness (SSD). The surgical procedure with transmastoid approach was completed in all cases without complications. Both subjects with CHL showed an increase in speech perception thresholds in quiet from preoperative unaided to 6 months postoperatively with BB of 37 dB, respectively, of 12 dB. The adolescent with SSD attained -3.1 dB unaided vs. -5.6 dB with the BB in the "speech and noise from the front" presentation and +0.5 unaided vs. -5.0 dB with the BB in the "speech from the unilateral deaf side/noise from the normal hearing side" presentation using the adaptive Oldenburg Sentence Test. The results show a straightforward surgical procedure and satisfactory functional gain after BB implantation also in children/adolescents. BB implantation in patients ≤18 years is currently an "off-label use" so that detailed information about alternative treatment options, operation risks and the lack of approval for use in children is essential.

The new mid-scala electrode array: a radiologic and histologic study in human temporal bones.

HYPOTHESIS: To analyze the quality of insertion of the newly developed midscala (MS) electrode, which targets a midscalar electrode position to reduce the risk of trauma to the lateral wall and the modiolus. BACKGROUND: Modern cochlear implant surgery aims for a safe intracochlear placement of electrode arrays with an ongoing debate regarding cochleostomy or round window (RW) insertion and the use of lateral wall or perimodiolar electrode placement. Intracochlear trauma after insertion of different electrodes depends on insertion mode and electrode design and may result in trauma to the delicate structures of the cochlear. METHODS: We performed a temporal bone (TB) trial with insertion of the MS electrode in n = 20 TB's after a mastoidectomy and posterior tympanotomy. Insertion was performed either via the RW or a cochleostomy. Electrode positioning, length of insertion, and angle of insertion were analyzed with rotational tomography (RT). TBs were histologically analyzed. Results of RT and histology were compared. RESULTS: Scala tympani (ST) insertion could be accomplished reliably by both RW and via a cochleostomy approach. In 20 TBs, 1 scala vestibuli insertion, 1 incomplete (ST), and 1 elevation of basilar membrane were depicted. No trauma was found in 94.7% of all ST insertions. RT allowed determination of the intracochlear electrode position, which was specified by histologic sectioning. CONCLUSION: The new MS electrode seems to fulfill reliable atraumatic intracochlear placement via RW and cochleostomy approaches. RT is available for evaluation of intracochlear electrode position, serving as a potential quality control instrument in human implantation.

Revision surgery due to magnet dislocation in cochlear implant patients: an emerging complication.

OBJECTIVES: To analyze the cause and effect of magnet dislocation in cochlear implant (CI) recipients requiring magnet revision surgery for treatment. STUDY DESIGN: Retrospective study. SETTING: Tertiary referral center. INTERVENTIONS: Case reports from 1,706 CI recipients consecutively implanted from January 2000 to December 2011 were reviewed. The number of cases requiring magnet revision surgery was assessed. RESULTS: Revision surgery involving magnet removal or replacement was indicated in 1.23% (21/1,706), of all CI recipients. Magnet dislocation occurring during magnetic resonance tomography (MRI), at 1.5 Tesla (T), with the magnet in place and with the application of compression bandaging around the head, was the main cause for revision surgery in 47.62% (10/21) of the affected cases. All 10 cases were implanted with Cochlear Nucleus cochlear implants. These events occurred, despite adherence to current recommendations of the manufacturer. CONCLUSION: The present study underlines that MRI examination is the main cause of magnet dislocation. The use of compressive bandaging when using 1.5-T MRI does not eliminate the risk of magnet dislocation. Additional cautionary measures are for required for conditional MRI. We recommend X-ray examination after MRI to determine magnet dislocation and avoid major complications in all cases reporting pain during or after MRI. Additional research regarding silicon magnet pocket design for added retention is needed. Effective communication of guidelines for precautionary measures during MRI examination in CI patients is mandatory for all clinicians involved. MRI in CI recipients should be indicated with caution.

Clinical outcome after cochlear implantation in patients with unilateral hearing loss due to labyrinthitis ossificans.

OBJECTIVES: Cochlear implantation (CI) is the treatment of choice in bilateral labyrinthitis ossificans (LO). The aim of this clinical case study was to evaluate audiologic and subjective outcomes after CI treatment for unilateral hearing loss (UHL) because of LO and to identify optimal timing for treatment. PATIENTS: Three subjects (age 40, 54, and 68 yr) with UHL because of LO were enrolled. Duration of deafness was 1.5, 12, and 120 months. INTERVENTION: After extensive consultation, testing with conventional contralateral routing of signal hearing aid and bone-anchored hearing instrument, CI candidacy was confirmed and CI surgery performed. MAIN OUTCOME MEASURES: Test of open-set speech recognition in background noise and sound localization were performed preoperatively, in unaided and aided conditions, and in the CI-aided condition, at 6 and 12 months postoperatively. Subjective assessment via the Speech, Spatial and Qualities scale (SSQ) and the Tinnitus Visual Analogue Scale was performed at preimplant and 12 months postimplant. CONCLUSION: The data show moderate-to-high hearing benefit after CI in 2 cases and no benefit for the third. SSQ and tinnitus scales show benefit from CI use in both cases. CI treatment should be performed as early as possible, ideally before signs of obliteration are evident. Counseling on all rehabilitation options is important.