Characteristics of sound localization in children with unilateral microtia and atresia and predictors of localization improvement when using a bone conduction device

Abstract

This study aimed to determine the characteristics of sound localization in children with unilateral microtia and atresia (UMA) and the influence of a non-surgical bone conduction device (BCD). Hearing benefits were evaluated by the word recognition score (WRS), speech reception threshold, the international outcome inventory for hearing aids (IOI-HA), and the Speech, Spatial, and Qualities of Hearing Test for Parent (SSQ-P). Sound localization was measured using broadband noise stimuli randomly played from seven loudspeakers at different stimulus levels [65, 70, and 75 dB sound pressure levels (SPLs)]. The average unaided WRS and speech-to-noise ratio (SNR) for UMA patients was 18.27 ± 14.63 % and −5 ± 1.18 dB SPL, and the average aided WRS and SNR conspicuously changed to 85.45 ± 7.38 % and −7.73 ± 1.42 dB SPL, respectively. The mean IOI-HA score was 4.57 ± 0.73. Compared to the unaided condition, the mean SSQ-P score in each domain improved from 7.08 ± 2.5, 4.86 ± 2.27, and 6.59 ± 1.4 to 8.72 ± 0.95, 7.61 ± 1.52, and 8.55 ± 1.09, respectively. In the sound localization test, some children with UMA were able to detect sound sources quite well and the sound localization abilities did not deteriorate with the non-surgical BCD. Our study concludes that for children with UMA, the non-surgical BCD provided a definite benefit on speech recognition and high satisfaction without deteriorating their sound localization abilities. It is an efficient and safe solution for the early hearing intervention of these patients.

The Effects of BCDs in Unilateral Conductive Hearing Loss: A Systematic Review

“…In all of the studies, the unaided and aided conditions were compared through prospective or retrospective analysis. Three of the studies recruited normal-hearing as control groups [ 6 , 7 , 8 ], whilst the majority of the studies were controlled before and after the study. Some studies included different patient groups [ 8 , 9 , 10 , 11 ].…”

“…The studies were done in the UK [ 13 ], USA [ 21 ], Canada [ 17 , 23 ], China [ 6 , 26 ], Germany [ 27 ], the Netherlands [ 7 , 11 , 14 , 18 , 19 , 20 , 22 ], Sweden [ 8 ], Australia [ 15 ], France [ 24 , 28 ], Italy [ 16 ], Poland [ 9 , 10 ], and Austria [ 25 ]. Patients of all ages are included in these studies, and both congenital and acquired UCHL are included.…”

“…The BCDs used are Bone-anchored hearing aids (BAHA) [ 8 , 11 , 14 , 18 , 20 , 21 ], Sophono [ 22 , 23 , 24 ], Baha Attract system [ 10 , 17 ], BoneBridge [ 7 , 25 ], as well as the ADHEAR hearing system [ 6 , 13 , 15 , 26 , 27 ].…”

Integrated microtia and aural atresia management

“…Parents should be made aware that they may not notice a behavioral difference in the early fitting of bone conduction aids, and some may feel that it “doesn't make a difference.” The goal of the early fitting is early adaptation to amplified sound for sensory integration into the child's experience in preparation for school age. While there is an increasing body of literature that indicates that the lack of sound localization in children with unilateral hearing loss is associated with increased difficulties with speech recognition in noise often found in the typical classroom environment ( 12 – 17 ), whether or not children with unilateral hearing loss from aural atresia actually gain benefit from amplification is still an emerging area of research with at least one group finding that bone conduction devices improved both sound localization and speech recognition in children with unilateral aural atresia ( 18 ).…”

Benefits of bone conduction hearing aid in children with unilateral aural atresia

“…Although in bilateral aural atresia hearing rehabilitation with bone conduction hearing aids is nowadays mandatory with a specific bilateral fitting 10 , in the latest years the necessity to rehabilitate a unilateral deficit has also emerged 11 . Indeed, unilateral hearing loss impacts sound localisation and speech perception in background noise, thus being a non-negligible factor in the hearing and speech evolution of the child [12][13][14] . Unfortunately, most of the literature on this topic is based on small studies 15,16 .…”