Telephone vs. Voice Over IP Speech Comprehension in Hearing Aided Subjects.

Despite modern hearing aids such as cochlear implants, speech comprehension during telephone conversation is challenging for hearing-impaired patients. On the one hand, conventional telephones transmit a limited spectrum of the acoustic signal compared to a normal conversation. On the other hand, lip reading during a phone call is generally not possible. As a result, speech comprehension during a telephone conversation is reduced. In previous studies, the authors demonstrated an improved speech comprehension for hearing-impaired patients using voice-over internet protocol (VoIP) telephony (Skype) compared to conventional telephony. New bluetooth-enabled hearing aids allow for direct transmission of the telephone signal to the hearing device. As the direct transmission is expected to improve signal-to-noise ratio, speech comprehension is tested in patients with bluetooth-enabled hearing aids for 4 different scenarios: 1. conventional telephony without bluetooth device 2. conventional telephony with bluetooth device 3. VoIP telephony without bluetooth device 4. VoIP telephony with bluetooth device