Effect of fundamental-frequency and sentence-onset differences on speech-identification performance of young and older adults in a competing-talker background

Abstract

This study investigated the benefits of differences between sentences in fundamental frequency (F0) and temporal onset for sentence pairs among listener groups differing in age and hearing sensitivity. Two experiments were completed with the primary difference between experiments being the way in which the stimuli were presented. Experiment 1 used blocked stimulus presentation, which ultimately provided redundant acoustic cues to mark the target sentence in each pair, whereas Experiment 2 sampled a slightly more restricted stimulus space, but in a completely randomized presentation order. For both experiments, listeners were required to detect a cue word ("Baron") for the target sentence in each pair and to then identify the target words (color, number) that appeared later in the target sentence. Results of Experiment 1 showed that F0 or onset separation cues were beneficial to both cue-word detection and color-number identification performance. There were no significant differences across groups in the ability to detect the cue word, but groups differed in their ability to identify the correct color-number words. Elderly adults with impaired hearing had the greatest difficulty with the identification task despite the application of spectral shaping to restore the audibility of the speech stimuli. For the most part, the primary results of Experiment 1 were replicated in Experiment 2, although, in the latter experiment, all older adults, whether they had normal or impaired hearing, performed worse than young adults with normal hearing. From Experiment 2, the benefits received for a difference in F0 between talkers of 6 semitones were equivalent to those received for an onset asynchrony of 300 ms between sentences and, for such conditions, the combination of both sound-segregation cues resulted in an additive benefit.

Auditory Training: Evidence for Neural Plasticity in Older Adults

“…In addition to a large body of work investigating speech perception difficulties in older adults (Busey, Craig, Clark, & Humes, 2010; Fogerty, Humes, & Kewley-Port, 2010; Humes, 2007; Humes, Burk, Coughlin, Busey, & Strauser, 2007; Humes, Kewley-Port, Fogerty, & Kinney, 2010; Lee & Humes, 2012), Humes and colleagues have extensively studied the effects of word-based auditory training on speech perception in older adults (Burk & Humes, 2007, 2008; Burk, Humes, Amos, & Strauser, 2006), and have demonstrated that training of words in noise generalizes to unfamiliar talkers and persists for at least 6 months (Burk & Humes, 2008). …”

Age-Related Changes in Objective and Subjective Speech Perception in Complex Listening Environments

“…Suboptimal working memory (especially in older individuals) is associated with reduced speech recognition ability in adverse listening situations (Akeroyd, 2008;Anderson, White-Schwoch, Parbery-Clark, & Kraus, 2013;Desjardins & Doherty, 2013;Humes, Lee, & Coughlin, 2006;Koelewijn, Zekveld, Festen, Rönnberg, & Kramer, 2012;Lee & Humes, 2012). There is also evidence that age-related changes in processing speed are related to a decline in speech perception performance in noise for older adults (Tun et al, 2002;Tun & Wingfield, 1999;Woods, Kalluri, Pentony, & Nooraei, 2013).…”

Competing Speech Perception in Middle Age

“…Background noise makes communication in many situations difficult for older listeners, especially when this noise consists of voices of other talkers (e.g., Desjardins and Doherty, 2013; Helfer, Chevalier, and Freyman, 2010; Helfer and Freyman, 2008, 2014; Humes and Coughlin, 2009; Humes et al, 2006; Lee and Humes, 2012; Rossi-Katz and Arehart, 2009; Tun and Wingfield, 1999). Competing speech situations require individuals to use both peripheral and cognitive resources in order to communicate successfully, as the multiple speech sources must be segregated, messages not of interest must be ignored, and attention often needs to be switched mid-conversation.…”