Equivalent irrelevant-sound effects for old and young adults.

Three experiments are reported in which a total of 182 old and 193 young adults recalled sequences of digits presented visually in silence or accompanied by office noise. In each experiment, an effect of irrelevant sound was found-that is, a reduction of serial recall due to auditory distraction. Old adults exhibited poorer serial recall than did young adults, but the irrelevant-sound effect was equivalent in both age groups. This was true even though the sound level of the irrelevant sound was adjusted to each individual's hearing capability, and the effect remained whether or not the difficulty of the serial recall task was equated across age groups. These results are problematic for the inhibitory deficit theory of cognitive aging, which predicts that old adults should be more susceptible to auditory distraction than are young adults.