Application of sentence tests in the investigation of speech intelligibility in quiet and noise in adult CI recipients supported with a hearing aid

Abstract

The investigations of speech intelligibility were carried out for 9 patients with a cochlear implant (CI), 1 male and 8 females, aged 18-69 (mean 41). In all cases deafness was recognized as postlingual. All patients were using the hearing aid (HA) on the ear opposite to the CI. The novelty of this work consisted in the application of new Polish sentence tests in the evaluation of the effect of supporting electrical hearing with a HA in noise conditions. The sentence tests (developed at the Institute of Acoustics, Adam Mickiewicz University in Poznań - European Union Project HEARCOM) were presented to patients in quiet and in noise conditions (speech bubble noise). The speech intelligibility was determined in two cases: when transmission was only via the CI and when the HA was also used. The presentation of tests was conducted for three angles (0o, -90o and +90o) in relation to the patient's head. The value of SRT (Speech Reception Threshold) was determined for the tests carried out in noise conditions. The improvement of the speech intelligibility was affirmed when the process of hearing via the CI was supported with a HA. The particularly essential difference was observed for the angle of +90o (HA-side). The results obtained in the investigations show that acoustic compensation in the range of the remaining audibility field to a great degree supports electrical hearing. This conclusion can be an important contribution to the application of the HA on the side opposite to the CI, especially in the noisy environment.