The effects of room acoustics and multiple talkers on speech intelligibility with normal hearing and hearing impaired individuals

Abstract

Many studies have shown the effect of hearing loss and spatial separation on multi-talker word identification ability in free-field listening conditions. However, little is known about the combination of room reflections and hearing impairment on understanding speech. The purpose of this study was to determine if the effect of room reflections on speech intelligibility was equal among normal hearing and hearing impaired listeners. Two acoustic generation techniques were employed to create the free-field and semi-reverberant listening conditions. Free-field listening conditions were created using virtual acoustic technology. Room reflections were added to the speech samples using dummy-head recordings in a semi-reverberant room. The word identification test used in the experiments was the Modified Rhyme Test (MRT), which afforded a multitude of phonemic pairs when phrases were played simultaneously. Thirty-three listeners in each group participated in each test condition. The hearing impaired listeners were below 60 years of age and exhibited a high frequency, cochlear hearing loss. The normal hearing listeners were age matched with the hearing impaired group. A difference in the type of phonemic identifications between the two techniques and the two groups were found. These phonemic contrasts between will be discussed individually.