Recognition of Speech With Dynamic Pitch Manipulation in Noise: Effects of Manipulation Methods.

PURPOSE: Dynamic pitch, which is defined as the variation in fundamental frequency in speech, is one of the acoustic cues that affect speech recognition in noise. Built on the evidence that a symmetrical manipulation of dynamic pitch led to poorer speech recognition, the present study examined the effect of an asymmetrical manipulation method on speech recognition in noise by younger and older adults. METHOD: Speech recognition accuracy in noise was measured from younger adults with normal hearing in Experiment 1, and speech reception threshold (in dB SNR) from older adults with normal hearing to mild-moderate hearing loss in Experiment 2. The dynamic pitch contours of the speech stimuli were manipulated using both symmetrical and asymmetrical methods. RESULTS: Younger adults recognized speech better in noise with asymmetrical than symmetrical manipulation, and with weakened than strengthened dynamic pitch. A substantial amount of variability was observed in a group of older listeners. This variability was predominately predicted by the listeners' age but not hearing thresholds or their ability to perceive dynamic pitch in fluctuating noise. CONCLUSIONS: The asymmetrical manipulation of dynamic pitch had a less negative effect than the symmetrical manipulation. This effect also interacted with pitch-change direction. These findings suggest the influence of perceptual naturalness on speech recognition with signal modification. Directions for future research are also discussed.

Speech Recognition in Noise Performance Measured Remotely Versus In-Laboratory From Older and Younger Listeners.

PURPOSE: This study examined the performance difference between remote and in-laboratory test modalities with a speech recognition in noise task in older and younger adults. METHOD: Four groups of participants (younger remote, younger in-laboratory, older remote, and older in-laboratory) were tested on a speech recognition in noise protocol with 72 sentences. RESULTS: While the younger remote group performed more poorly than the younger in-laboratory group, older participants' performance was comparable between the two modality groups, particularly in the easy to moderately difficult conditions. These results persisted after controlling for demographic variables (e.g., age, gender, and education). CONCLUSION: While these findings generally support the feasibility of remote data collection with older participants for research on speech perception, they also suggest that technological proficiency is an important factor that affects performance on remote testing in the aging population.