[The role of mono- and binaural hearing aid in the rehabilitation of the adult patients presenting with hearing impairment].

The objective of the present study was to compare the effectiveness of mono- and binaural hearing aids in the rehabilitation of the adult patients of different age presenting with chronic symmetric hearing loss (CSHL). A total of 263 subjects at the age from 50 to 88 years complaining of moderate to severe (grade I-IV) chronic symmetric hearing impairment were available for the examination. Following the ENT examination with the application of pure tone audiometry and impedancometry, the participants of the study were supplied with the individually fitted digital behind-the-ear hearing instruments and underwent speech audiometry in the free sound field. The intelligibility of polysyllabic words in the calm and noisy environment was evaluated. A significant deterioration of the intelligibility was documented both under the quiet and noisy conditions. Its severity increased with the patients' age and the degree of hearing impairment. The comparison of the results of speech audiometry in the patients using either a single or two hearing aids gave evidence that binaural hearing aids were more efficient than monoaural ones in 86% of the patients. Re-examination of the same patients one year after the completion of the first study has demonstrated that 59% of them became permanent users of the hearing aids with 47% of them making regular use of simultaneously two hearing aids. It is concluded that speech audiometry in the free sound field can be recommended as a highly informative method that allows to substantiate the reasonable choice between the mono- and binaural hearing aids for the adult patients presenting with hearing impairment.