This study compared pure-tone threshold data, acoustic reflex threshold data, and loudness growth data for a group of 25 hyperacusic male subjects vs. a group of 13 nonhyperacusic male subjects. Pure-tone thresholds and acoustic reflex thresholds were obtained in 5-dB steps, using revised Hughson-Westlake procedures. Loudness growth functions were obtained with a fractionation (method of adjustment) procedure whereby the subjects doubled loudness, using a 1-dB step attenuator. Results suggest that loudness growth was significantly different for the hyperacusic subjects compared to the nonhyperacusic subjects, but no significant differences in pure-tone thresholds or acoustic reflex thresholds were observed. When the hyperacusic group was divided into subgroups, however, the endocrine disorder subgroup had significantly lower acoustic reflex thresholds compared to the other subgroups of hyperacusic subjects. No other significant differences among the subgroups were noted.

Hyperacusis, as defined here, is a relatively rare condition in which the patient, with or without hearing loss, experiences severe loudness discomfort to everyday environmental sound levels. The case studies of 14 patients with severe hyperacusis are described; all wore passive attenuators (earplugs and/or earmuffs) in an attempt to alleviate their discomfort, frequently producing communication difficulties. These subjects were fitted binaurally with experimental electronic loudness suppression devices housed in in-the-ear casings. The devices supplied low-level amplification followed by an extreme form of amplitude compression for moderate or high-level inputs in an attempt to reduce loudness discomfort without reducing audibility. Many of the subjects were found to function with a wider dynamic range with the active devices compared with passive attenuators or the unoccluded ear, and most reported that they benefited from the devices in at least some listening situations.

Three randomizations of a list of twenty-five words were recorded by a single talker on separate days and under identical conditions. One of the recordings was rerecorded three times and these dubbings were acoustically corrected, cut, and spliced into the three different orders. Two groups of twelve subjects each were tested. One group listened to the three independent recordings, the other to the three randomizations of the single reading. Statistically significant differences in listener performance were found among the three independent readings of the word list, but no differences were found among the randomizations of the single reading. These results indicate that repeated readings of a list of words do not necessarily give equivalent forms of a test of speech discrimination.

No abstract

Eight normal-hearing male observers were trained to detect brief acoustic pips during a YES-NO procedure until a consistent correct-response rate of approximately 80% was achieved. The pips were presented to one ear at an equivalent level during reference, control, and experimental conditions. During the experimental conditions, the pips were presented at 90° re an on-going 50-Hz sinusoid, which was presented ipsilaterally at four subliminal levels (−10, −20, −30, and −40 db SL). Utilizing a balanced design, four observers received the signals in the right ear and four received them in the left. Higher correct-response rates were observed when the 50-Hz sinusoid was presented at −10 and −20 dB SL than during any of the other conditions. This increase in the correct-response rate for the pips in the presence of a subliminal 50-Hz sinusoid was called the Subliminal Sensitization Effect (SSE). When the effect of level was evaluated, it was noted that the SSE broke down when the 50-Hz sinusoid was between −20 and −30 dB SL. Analyses of group differences revealed a greater SSE for the observers who received the signals in the right ear.