Effects of two procedural modifications of the frequency of false-alarm responses during pure-tone threshold determination.

In normal-hearing young adults without tinnitus, HTLs were collected using 5-db steps, and false alarms (FA's) noted, at octaves from .25-8 kc/s either in quiet or in a white noise background set at 15 db sensation level for each S. In Exper. I (N:10), the ascending and descending modes did not yield significantly different numbers of FA's in quiet; in noise, FA's increased significantly vs the quiet condition in the ascending but not in the descending modes, while in noise, furthermore, FA's increased significantly for the ascending vs the descending mode. In a similar Exper. II (N:10), the 4 combinations (single- and pulsed-tone presentations, ascending and descending modes) showed that FA's were significantly fewest with a descending, pulsed-tone technique. It was recommended that when FA's pose a problem when using the ascending mode, single-tone technique (ASHA guidelines), the clinician change to the descending, pulse-tone technique to reduce FA's by increasing the stimulus certainty under difficult listening circumstances.