2.3 Device and listening conditions
An adhesive BCD (DHEAR, MED-EL, Innsbruck, Austria) was used in the
current study. For all experimental conditions, the devices were set to
omnidirectional mode, and the volume was adjusted according to patients’
preferences.
Children with UMA were tested with the BCD off (unaided condition) and
on (aided condition) (Supplementary Fig. 1b). Children with NH were
measured with both ears unplugged (UP condition) as normal controls.
When measuring the sound localisation, control listeners were tested
with plugging (P condition) to stimulate an acquired UCHL to reveal the
characteristics of directional hearing of acquired UCHL. Plugging was
performed by covering an ear with an earmuff (Peltor X5A; 3M Company,
MN, USA), along with a foam earplug (E-A-R soft; 3M Company) inserted
into the external auditory canal. For the UMA group,
unaided
audiological tests were performed on the day when receiving the BCD and
aided audiological tests were measured after a mean period of 9.27 ±
1.85 weeks. For the NH group, all tests were performed in one visit.
2.4
Subject satisfaction
The
Chinese version of the international outcome inventory for hearing aids
(IOI-HA)
(IOI-HA) 13 was handed out to all patients at the end
of the
follow-up.
The IOI-HA consists of seven
items:
daily use, benefit, residual activity limitations, satisfaction,
residual participation restrictions, impact on others, and quality of
life.
Each
item has a five-point rating scale, with higher ratings reflecting
better outcomes (or fewer residual difficulties).