Effects of cueing in auditory temporal masking.

PURPOSE

In a landmark study, B. A. Wright et al. (1997) reported an apparent backward-masking deficit in language-learning-impaired children. Subsequently, the controversial interpretation of those results has been influential in guiding treatments for childhood language problems. This study revisited the temporal-masking paradigm reported by B. A. Wright et al. to evaluate adult listener signal/masker uncertainty effects for some of their key stimulus conditions. New signal conditions presented off frequency from the masker also were evaluated to assess conditions of reduced signal/masker confusion.

METHOD

Masked detection was measured for 20-ms sinusoids (480, 1000, or 1680 Hz) presented at temporal positions before, during, or after a gated narrowband (bandwidth = 600-1400 Hz) masker. Listener uncertainty was investigated by cueing various stimulus temporal properties with a 6000-Hz sinusoid presented contralateral to the test ear.

RESULTS

The primary cueing effect was measured in the backward-masking condition for the cue gated simultaneously with the on-frequency 1000-Hz signal. The resulting cued masked-detection threshold was reduced to quiet threshold. No significant cueing effects were obtained for other signal temporal positions in the masker or for any off-frequency signal conditions.

CONCLUSIONS

These results for normal adult listeners indicate that on-frequency backward masking can be eliminated by cueing the signal, and thus, these findings raise the possibility that the deficit reported by B. A. Wright et al. for language-learning-impaired children may reflect inordinate signal/masker confusion, rather than a temporal-processing deficit per se.