Single-Sided Deafness—Outcomes of Three Interventions for Profound Unilateral Sensorineural Hearing Loss: A Randomized Clinical Trial

Implantable hearing devices in clinical practice. Systematic review and consensus statements

Objective

Implantable hearing devices represent a modern and innovative solution for hearing restoration. Over the years, these high-tech devices have increasingly evolved but their use in clinical practice is not universally agreed in the scientific literature. Congresses, meetings, conferences, and consensus statements to achieve international agreement have been made. This work follows this line and aims to answer unsolved questions regarding examinations, selection criteria and surgery for implantable hearing devices.

Materials and methods

A Consensus Working Group was established by the Italian Society of Otorhinolaryngology. A method group performed a systematic review for each single question to identify the current best evidence on the topic and to guide a multidisciplinary panel in developing the statements.

Results

Twenty-nine consensus statements were approved by the Italian Society of Otorhinolaryngology. These were associated with 4 key area subtopics regarding pre-operative tests, otological, audiological and surgical indications.

Conclusions

This consensus can be considered a further step forward to establish realistic guidelines on the debated topic of implantable hearing devices.

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

OBJECTIVES

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.

DESIGN

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.

RESULTS

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.

CONCLUSIONS

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.

Choice of treatment evaluated after trial periods with bone conduction devices and contralateral routing of sound systems in patients with single-sided deafness

Objectives

Patients with single-sided deafness (SSD) may experience difficulties with speech perception in noise, sound localization, have tinnitus and experience a reduced quality of life (QoL). contralateral routing of sound hearing aids (CROS) or bone conduction devices (BCD) may partly improve subjective speech communication and QoL in SSD patients. A trial period with these devices can help in making a well-informed choice of treatment. Our aim was to evaluate factors influencing the choice of treatment made after a BCD and CROS trial period in adult SSD patients.

Methods

Patients were randomized in the: "first BCD, then CROS" or "first CROS, then BCD" trial period group. After the BCD on headband and CROS were tested for 6 weeks each, patients choose for BCD, CROS or no treatment. Primary outcome was the distribution of choice of treatment. Secondary outcomes included the association between the choice of treatment and patient characteristics, reasons for treatment acceptance or rejection, device usage during the trial periods, and disease-specific QoL outcomes.

Results

Of 91 patients randomized, 84 completed both trial periods and made their choice of treatment: 25 (30%) BCD, 34 (40%) CROS, and 25 (30%) no treatment. No characteristics were found to be related to choice of treatment. Top three reasons for acceptance or rejection were: device (dis)comfort, sound quality and (dis)advantage of subjective hearing. Average daily device use during the trial periods was higher for CROS than for BCD. Choice of treatment was significantly related with both duration of device usage and greater improvement of QoL after the corresponding trial period.

Conclusion

The majority of SSD patients preferred BCD or CROS over no treatment. Evaluating device usage, discussing treatment (dis)advantages and disease-specific QoL outcomes after trial periods are to be considered during patient counseling and could facilitate whether to choose one of these treatments.

Level of evidence

1B.

[Compensation effect of hearing aid on speech recognition in noise in patients with unilateral hearing loss]

Objective:The aim of this study was to investigate the speech recognition in noise in patients with unilateral hearing loss（UHL）, and explore the compensation effect of behind-the-ear（BTE） hearing aid on speech recognition in patients with varied degrees of UHL. Methods:Twenty-five participants with UHL were divided into two groups according to the degree of hearing loss: one group included subjects with unilateral moderate and moderately severe hearing loss and another one included subjects with unilateral severe and profound hearing loss. Fifteen healthy subjects with normal hearing were enrolled as the control group. The speech recognition thresholds and speech recognition scores at fixed signal noise ratio（SNR） in UHL participants with and without BTE hearing aid were tested in the sound field and compared with those in the control group. One-way ANOVA was used to examine the significance of the difference between UHL participants and control group, and paired t-test was used to analyze the compensation effect of hearing aid on speech recognition in noise in UHL participants. Results:The speech recognition thresholds were significantly higher in both UHL groups（P<0.01） compared with the control group, there was no significant difference between two UHL groups. And the speech recognition scores were significantly lower when the SNR was fixed（P<0.01）, and there were no significant differences between two UHL groups. When fitting BTE hearing aid, the speech recognition thresholds of the two groups significantly decreased（P<0.01）, and the speech recognition scores significantly improved（P<0.01）. Conclusion:Patients with above moderate UHL presented a significant decrease in performance of speech recognition in noise, and fitting BTE hearing aid on the affected ear had a positive compensation effect.

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

Background and Objectives

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).

Materials and Methods

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.

Results

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.

Conclusions

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.

Congenital Unilateral Hearing Loss: Characteristics and Etiological Analysis in 121 Patients

OBJECTIVE

To describe the characteristics and etiological analysis in patients with congenital unilateral hearing loss.

STUDY DESIGN

Retrospective cohort analysis.

SETTING

Tertiary referral center.

PATIENTS

Children with permanent congenital unilateral hearing loss born between 2007 and 2018. Patients were referred after universal newborn hearing screening or by a colleague to confirm the diagnosis and perform etiological examinations.

MAIN OUTCOME MEASURES

Hearing loss type, severity, and evolution linked with the results of etiological testing.

RESULTS

In the 121 included children, aural atresia is the leading cause of congenital unilateral hearing loss (32%), followed by structural anomalies (19%) and cCMV (13%), whereas 24% remained idiopathic after etiological work-up. Severity is mainly moderately severe (33% with 56-70 dB hearing loss, majority aural atresia) or profound (31% with > 90 dB hearing loss, predominantly cochlear nerve deficiency). Syndromic features were present in 26%. Although discussed with all parents, only 26% of the children regularly used hearing amplification.

CONCLUSIONS

Congenital conductive unilateral hearing loss is mainly caused by aural atresia, which proportion in congenital unilateral hearing loss proved higher than previously reported. Cochlear nerve deficiency and cCMV are the predominant etiologies of congenital unilateral sensorineural hearing loss. Etiological work-up in affected patients is mandatory as it might impact the approach, and syndromic features should be actively searched for.