Speech Perception Benefit for Children with a Cochlear Implant and a Hearing Aid in Opposite Ears and Children with Bilateral Cochlear Implants

Abstract

The aims of the present study are to investigate: (1) the effect of using a hearing aid (HA) or a second cochlear implant (2nd CI) on speech recognition in noise for children; (2) the ability to perceive phoneme groups of different frequencies when using a CI and an HA in opposite ears (bimodal fitting) and when using a CI in each ear (bilateral implant fitting), and (3) the relationship between aided thresholds in the HA ear and bimodal advantage. Thirteen school-age children who consistently used a bimodal or bilateral implant fitting participated. Perception was evaluated using consonant-nucleus-consonantwords presented from in front with noise from either side. Significant bimodal or bilateral CI advantage in speech perception was demonstrated by most subjects in at least 1 noise condition. Comparisons indicated that the bimodal advantage obtained by the bimodal subjects was greater than the bilateral CI advantage obtained by the bilateral-implant subjects in the noise front condition, but also suggested that the 2nd CI may provide more functional advantage in real life. The mechanisms underlying the advantage provided by the second device appear to be different in the bimodal and bilateral groups. Information transmission analysis did not show a clear difference between the groups in the pattern of advantage across phoneme groups. For the bimodal subjects, those with better aided thresholds at low frequencies and poorer aided thresholds at 4 kHz demonstrated greater bimodal advantage. Overall, these findings encourage the use of bimodal and bilateral implant fittings for children, provide insight into the individual variability in bimodal outcome, and enhance understanding of the differences between an HA and a 2nd CI when used together with an implant in the opposite ear.

Asymmetric Hearing During Development: The Aural Preference Syndrome and Treatment Options

“…75,94 Thus, even in the worst condition (early onset, long duration of single-sided deafness), there is some hope for stimulating hearing in the deaf ear and establishing binaural hearing, with demonstrable benefits already realized. 64-66,68-70, [131][132][133][134] On the other hand, these skills remain abnormal, reflecting persistent reorganization after single-sided hearing. Without focused training, 3 to 4 years of bilateral implant use was not sufficient to reduce the preference of the first-implanted ear…”

A comparison of the speech recognition and pitch ranking abilities of children using a unilateral cochlear implant, bimodal stimulation or bilateral hearing aids

“…Selective attention to information from the ear with the better SNR allows for improved speech recognition. While adult users of BMS benefit from the head shadow effect regardless of which ear has the better SNR [24], child users of BMS exhibit no significant head shadow advantage when the better SNR is on the side of their HA [24,25]. It appears that children using BMS may be more dependent upon information from their CI for speech recognition; children from two recent studies scoring higher when both their CI and HA had the same binaural processing mechanisms that assist speech recognition in noise, outcomes differ between adults and children, the latter only appearing to benefit from 'binaural redundancy.'…”

“…In contrast, children in the BMS group performed at levels similar to their CI-only peers, suggesting that they may have been focusing upon the limited pitch information provided via their implants. Similarly, research has shown that postlingually deafened adult users of BMS are able to utilise the head shadow effect to improve speech recognition in noise regardless of whether their CI or HA has the better SNR [24], while children are only able to utilise the head shadow effect when their CI has the better SNR [25,26]. It appears that unlike their postlingually deafened counterparts, prelingually deafened children using BMS may be less adept at using the acoustic signal from their HA.…”

Impact of hearing aid use on auditory perception and verbal short-term memory in children with bimodal stimulation

“…Preoperative HAs use in our subjects also developed early skills in verbal short-term memory, which were proven to be important predictor of later vocabulary and language growth in children with CI ). Bimodal hearing stimulation in children allows better speech intelligibility in children, both in quiet and in noise (Lee et al, 2008, Keilmann, & et al, 2009Mok et al, 2010). Children with longer experience with bimodal hearing after cochlear implantation in our study had better perception of nonsense words and sentences, which demands capacity for language understanding and developed short-term verbal memory.…”