Binaural Hearing Using the ADHEAR Bone Conduction System in the Monaurally Occluded Ear.

INTRODUCTION: The study aimed to investigate binaural cues in the rehabilitation of unilateral occluded ears with a bone conduction hearing aid. METHODS: The study sample consisted of 40 adult volunteers with normal hearing. Unilateral pseudo-conductive hearing loss was induced by inserting an earplug into the external auditory canal (EAC) and silicone material in the concha for ear impression. The adaptive speech-in-noise test (Italian Matrix test) was performed in three spatial orientations to assess binaural cues (summation, squelch, and head shadow effects). All evaluations were performed in the normal condition, after EAC occlusion, and after application of an adhesive bone conduction hearing aid. Binaural contrast differences were calculated in the three conditions. RESULTS: In the EAC occlusion condition, there was a significant increase in the signal-to-noise ratio (SNR) in both the S0N0 (2.4 dB) and the S90N-90 (7.7 dB) settings, and a slight albeit significant increase in the S0N90 setting (1.35 dB). After fitting the BC hearing aid, there was a reduction of -1.8 dB SNR (p < 0.001) in the S0N0 setting and -2 dB (p = 0.003) in the S90N-90 setting. There was no improvement in the SNR (p = 0.405) in evaluation of the squelch effect (S0N90). These data were corroborated by a better binaural contrast due to a reduction in the summation effect in the monaural occlusion condition and a subsequent reduction in binaural contrast after fitting the hearing aid due to an increase in the summation effect (-2.5 dB vs. 0.3 dB; p < 0.001). CONCLUSIONS: Application of a bone conduction hearing aid in unilateral pseudo-conductive hearing loss strengthens speech recognition of noise by improving the summation effect and impeding the shadow effect of the head; however, there appears to be no improvement in speech perception in noise due to spatial release from masking.

Speech in Noise With Bilateral Active Bone Conduction Implant for Conductive and Mixed Hearing Loss.

OBJECTIVE: To evaluate speech in noise results and subjective benefit in bilateral active bone conduction implant (ABCI) for bilateral mixed hearing loss. STUDY DESIGN: Prospective, comparative. SETTING: Ear, Nose and Throat Unit, Department of Surgical Sciences, University of Turin. PATIENTS: Seven patients with conductive/mixed hearing loss. INTERVENTIONS: Patients underwent simultaneous or sequential bilateral surgery for ABCI. MAIN OUTCOME MEASURES: The speech intelligibility in noise was assessed with the Ita Matrix test in summation, squelch and head shadow settings. First, the tests were performed with one device activated in the ear with lower speech recognition score, then with both devices. Patients filled in an Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire to investigate the hearing aid benefit. RESULTS: When bilateral devices were activated, an improvement of signal-to-noise ratio was observed in all settings. The difference between bilateral and unilateral stimulation is 4.66 dB ( p = 0.016) in the summation, 2.24 dB ( p = 0.047) in the squelch, 7.50 dB ( p = 0.016) in the head shadow setting.Looking at the APHAB global score (GS), patients report lower mean scores, hence less difficulties, when using two devices (GS, 21.9%; standard deviation (SD), 8.28) rather than one (GS, 33.0%; SD, 10.24) ( p = 0.018). CONCLUSION: In symmetric mixed bilateral hearing loss, rehabilitation with an ABCI fitted bilaterally shows audiologic advantages in speech perception in noise, not only thanks to the summation effect and by reducing head shadow but also by improving the binaural unmasking based on the squelch effect. Audiometric outcomes are confirmed by the GSs obtained in the APHAB questionnaire.

Cochlear Implant Outcomes in Prelingually Deafened Adults with and without Sound Deprivation: Are There Differences in Quality of Life?

BACKGROUND Indications for cochlear implantation (CI) are constantly being updated, and with them, the audiometric results achieved by patients. Patient satisfaction should always be considered, even in patients with lower audiological results. The aim of the present study was to compare quality of life (QoL), self-perceived hearing benefit, and audiometric results between prelingually and postlingually deafened patients, with and without sound deprivation, after CI. MATERIAL AND METHODS The sample included 46 patients with bilateral sensorineural hearing loss: 22 postlingually deafened and 24 prelingually deafened, further subdivided into sound-deprived (n=10) and non-sound-deprived (n=14). Auditory performance was evaluated with pure tone audiometry, speech recognition scores (SRS), and self-perceived hearing benefit, whereas QoL was evaluated with 2 self-reported questionnaires (Comprehensive Cochlear Implant Questionnaire and World Health Organization Quality of Life-BREF). RESULTS Audiometric results were worse in the prelingually deafened than in the postlingually deafened group, and worse in the prelingually deafened patients with sound deprivation. There was no marked difference in perceived CI benefit or QoL between the 2 groups or within the 2 prelingually deafened subgroups. No correlation was found between SRS and duration of CI use or between QoL and SRS in the prelingually and postlingually deafened groups. CONCLUSIONS Our findings demonstrate better auditory performance for the postlingually deafened group and no differences in perceived QoL or benefit of CI between the groups. The sound-deprived patients had equal scores on the perceived QoL questionnaire. These analyses suggest that sound-deprived, prelingually deafened patients may benefit from CI.

Stapedial Reflex: A Possible Novel Biomarker of Early Bulbar Involvement in Amyotrophic Lateral Sclerosis Patients.

BACKGROUND AND AIM: Amyotrophic lateral sclerosis (ALS) is a neuromuscular progressive disorder, characterized by limb and bulbar muscle wasting and weakness. 30% of patients present a bulbar onset, while 70% a spinal outbreak, although most of them develop bulbar impairment later on. Due to the lack of an early biomarker of bulbar involvement, we chose to evaluate the role of stapedial reflex (SR) in order to predict preclinical bulbar impairment in ALS. MATERIALS AND METHODS: We enrolled 36 ALS patients. We assessed revised-ALS functional-rating-scale and SR for a total of 4 visits. We established the presence of SR, acoustic reflex latency test (ARLT), and SRs Decay. Patients who had not develop bulbar signs at fourth visit continued follow-up up to 15 months. Data were analyzed by using Mann-Whitney U test, Friedman test, and Cox regression analysis. RESULTS: We observed that SRs Decay at 500 and 1,000 Hz is the first parameter of SR to get altered in all ALS patients before the development of bulbar impairment. Twenty-eight patients developed bulbar impairment during the study. We highlighted a correlation between the progression rate of disease and both time of SRs Decay alteration and time of bulbar impairment from disease onset. Four patients who did not develop bulbar impairment had a progression rate lower than the other ones (p < 0.05). DISCUSSION AND CONCLUSIONS: This study shows that SR Decay test could be a sensitive measure for detecting pre-symptomatic bulbar involvement in ALS and could represent a simple, noninvasive, and useful biomarker of disease progression.