A comparison of video versus conventional visual reinforcement in 7- to 16-month-old infants.

PURPOSE: To compare response patterns to video visual reinforcement audiometry (VVRA) and conventional visual reinforcement audiometry (CVRA) in infants 7-16 months of age. METHOD: Fourteen normal-hearing infants aged 7-16 months (8 male, 6 female) participated. A repeated measures design was used. Each infant was tested with VVRA and CVRA over 2 different sessions. The total number of head turns prior to habituation, hit rate (response consistency), false alarm rate, and sensitivity for each reinforcement condition were evaluated. RESULTS: No significant differences were found between the 2 reinforcement methods for total number of head turns, hit rate, false alarm rate, or sensitivity. Overall, results showed no difference between the 2 reinforcer conditions in infants 7-16 months of age. CONCLUSION: The results of the present study suggest that infants in the 7- to 16-month-old age range respond similarly to VVRA and CVRA as measured by response consistency and false alarm rate. VVRA is, therefore, a viable option for testing hearing in infants. However, prior to clinical implementation, the effectiveness of VVRA should be explored in infants with hearing loss.

The objective and subjective evaluation of multichannel expansion in wide dynamic range compression hearing instruments.

PURPOSE: The effects of multichannel expansion on the objective and subjective evaluation of 20 listeners fitted binaurally with 4-channel, digital in-the-ear hearing instruments were investigated. METHOD: Objective evaluations were conducted in quiet using the Connected Speech Test (CST) and in noise using the Hearing in Noise Test (HINT) at 40, 50, and 60 dB SPL. Subjective evaluations were conducted by having each participant (a) rate their satisfaction regarding the amount of noise reduction they perceived daily and (b) indicate which expansion condition they preferred overall after a 2-week trial. Three expansion settings were programmed into the hearing aids: 4-channel expansion, expansion restricted to Channels 1 and 2 only, and expansion off. RESULTS: Listeners performed significantly better in quiet (CST) and in noise (HINT) for the off condition than for either multichannel condition; however, restricting expansion to Channels 1 and 2 improved objective performance in quiet and in noise relative to the 4-channel condition. Conversely, satisfaction ratings were significantly greater for both multichannel conditions than for the off condition; however, satisfaction ratings were similar for the restricted and the 4-channel conditions. Overall, listeners preferred any form of multichannel expansion to no expansion; however, overall preference was similar for the restricted and the 4-channel conditions. CONCLUSIONS: Hearing instrument users prefer the use of multichannel expansion despite the fact multichannel expansion may significantly reduce the recognition of low-level speech in quiet and in noise. Although restricting expansion to Channels 1 and 2 (i.e., 2000 Hz and below) maintained subjective benefit for wide dynamic range compression hearing instrument users, the recognition of low-level speech was not completely preserved.

The objective and subjective evaluation of low-frequency expansion in wide dynamic range compression hearing instruments.

The effects of low-frequency expansion on the objective and subjective evaluation of four channel in-the-ear hearing instruments was investigated. Three expansion settings were programmed in each device: expansion off, expansion restricted to channel one, and expansion restricted to channels one and two. Objective evaluations were conducted in quiet (Connected Speech Test) and in noise (Hearing in Noise Test) with speech levels fixed at 40 dB SPL. Subjectively, each participant rated expansion satisfaction in quiet and listening to low-level speech in a sound-treated room then indicated the expansion condition preferred overall. Listeners performed significantly better in quiet and in noise for the Off and Channel 1 conditions than the Channels 1 and 2 condition; however, performance was similar between the Off and Channel 1 conditions. Expansion effects on listener satisfaction ratings depended on the listening environment. Overall, listeners preferred expansion in Channel 1 to expansion in Channels 1 and 2; however, preference was not significantly different between the Channel 1 and Off conditions. Results indicate restricting expansion to 1000 Hz overcomes speech-recognition deficits observed with expansion active across a broader spectrum without significantly reducing subjective benefit or preference.