Age-associated degeneration of backward masking task performance: evidence of declining temporal resolution abilities in normal listeners.

A backward masking paradigm was employed to investigate temporal resolution capabilities in normal-hearing subjects of increasing chronological age. Results have documented: (1) a 2-, 4-, 8-, and 11-fold decibel magnitude difference for averaged psychoacoustic functions when comparing data obtained from young adults to those of elderly listeners; (2) that backward masking function slopes become significantly steeper with age, especially at very short interstimulus intervals; (3) a significant interaction between age and target frequency; (4) a linear age-associated decrement in presumed temporal resolution abilities, and (5) no significant target frequency difference nor any ear differences existed. Both end organ and central nervous system mechanisms were considered in explaining these findings.