Age-Related Deficits in the Processing of Fundamental Frequency Differences for the Intelligibility of Competing Voices

A common complaint of older listeners is that they can hear speech, yet cannot understand it, especially when listening to speech in a background noise. When target and competing speech signals are concurrently presented, a difference in the fundamental frequency (ΔF0) between competing speech signals, which determines the pitch of voice, can be an important and commonly occurring cue to facilitate the separation of the target message from the interfering message, consequently improving intelligibility of the target message. To address the question of whether the older listeners have reduced ability to use ΔF0 and how the age-related deficits in the processing of ΔF0 are theoretically explained, this paper is divided into three parts. The first part of this article summarizes how the speech-communication difficulties that older listeners have are theoretically explained. In the second part, literatures on the perceptual benefits from ΔF0 and the age-related deficits on the use of ΔF0 are reviewed. As a final part, three theoretical models explaining the general processing of ΔF0 are compared to discuss which better explains the age-related deficits in the processing of ΔF0.