Effect of spectrally-remote maskers on sentence recognition by adults and children

Abstract

Adults display improved detection of a signal in noise when the spectral frequency of that signal is known, relative to when it is unknown. In contrast, infants do not display this improvement, suggesting that they monitor all frequencies equally, even when it is not advantageous to do so. To assess the impact of this “spectral attention” development during speech recognition, sentences in noise were lowpass filtered at 1500 Hz and presented along with spectrally remote low-noise noise maskers that produced no spectral overlap of peripheral excitation. As anticipated, sentence recognition by adults was not affected by the presence of remote maskers, irrespective of their bandwidth and spectral location. This result was also observed in a group of 7-year-old children. However, the youngest children tested (5-year-olds) displayed poorer sentence recognition in the presence of the remote maskers, suggesting that they were unable to focus attention on the spectral region of speech. The current results suggest that an important step occurs in the development of auditory spectral attention around age 6. These results may also help explain why children typically require more favorable signal-to-noise ratios than adults to achieve similar levels of speech performance in noise. [Work supported by NIH.]