Better Speech Recognition with Digital RF System in Study of Cochlear Implants

Hearing aid wearers often have difficulty understanding speech in the presence of background noise and reverberation (J Acous Soc Am 2008;124[5]:3064-3075; J Acoust Soc Am 1978;63[2]:533-549). They also may run into trouble when the signal of interest originates from across a large room. Remote microphone hearing assistive technology (HAT), more commonly referred to as a personal frequency modulation (FM) system, generally is the most effective method to improve performance in such challenging listening situations (J Speech Hear Disord 1984;49[4]:409-418; J Speech Hear Disord 1984;49[3]:278-286 ; Am J Audiol 2010;19[1]:36-45). These systems capture the signal of interest near its source, leading to a much more favorable signal-to-noise ratio (SNR) compared with that at the microphone of the hearing aid. Taking this information into account, we compared different types of hearing assistive technology to see if one approach was better than another in these difficult listening environments. We found that cochlear implant recipients using a digital radio frequency (RF) system had better speech recognition, especially at high noise levels, than those using other technologies.