Speech Recognition Ability of Children with Unilateral Sensorineural Hearing Loss As a Function of Amplification, Speech Stimuli and Listening Condition

The purpose of this investigation was to examine three types of audiological recommendations [unaided, CROS (contralateral routing of signals) and personal FM system] and their impact upon speech recognition ability of children with unilateral sensorineural hearing loss. Each of these recommendations was tested under three listening conditions encountered in a classroom [monaural direct (MD), monaural indirect (MI), midline signal/omnidirectional noise (MS/ON)] with two types of speech materials (Nonsense Syllable Test and an American English adaptation on the Bamford-Kowal-Bench Sentence Lists). These experimental conditions were simulated in a classroom, recorded on audiotape, and played back to subjects under headphones to control such factors as signal-to-noise ratio, earmold fit, and head shadow effects. Six school-age children with unilateral hearing losses between 56 and greater than 120 dB HL (PTA) were evaluated using a repeated measures design. The children experienced the most listening difficulty in the MI condition when they were unaided. The CROS aid improved speech recognition in this condition but degraded speech recognition in the MD condition. The FM system was the only audiological recommendation to produce uniformly high speech recognition scores across all listening conditions with both types of speech materials. Implications for the audiological management of unilaterally hearing-impaired children in the classroom are discussed.