Table 6.
Summary of studies employing temporal-masking paradigms in listeners with sensorineural hearing loss. The major studies reviewed in this paper are listed in the first column in the order in which they are discussed in Section II-F-1. The second column describes the type of temporal-masking paradigm employed. The third column describes the characteristics of the probe stimulus and the fourth column the characteristics of the masker. The fifth column (Thresh. Match?) provides information concerning the use of threshold matching to simulate hearing loss (with the noise-masking threshold-elevation procedure abbreviated as NM). The sixth column gives the number (No.) of subjects (Ss) and either the range or the mean (X̄) of ages in years of the NH and HI groups. The final column summarizes key comparisons of NH and HI performance.
| Study | Masking Paradigm | Probe Stimulus | Masker | Thresh. Match? | No. and Ages (Years) of Ss | Summary of Findings |
|---|---|---|---|---|---|---|
| Kidd et al. (1983) | Forward Masking | 3.0 kHz; 20 msec | 3.0 kHz; 35 or 300 msec; 20 to 100 dB SPL | NM | 2 NH: "Young Adults" 5 HI: "Young Adults" |
NH listeners had higher masked thresholds for 300 msec masker compared to 35 msec masker; HI listeners had similar amounts of threshold shift for both masker durations; NM NH listeners had 30-dB higher masked thresholds than NH listeners for both masker durations |
| Nelson & Freyman (1987) | Forward Masking | 1.0 kHz; 20 msec; levels in range of 5 to 30 dB SL | 1.0 kHz; 200 msec | No | Unknown | For NH listeners, time constant of temporal masking functions was roughly 50 msec; for HI listeners, time constant was 1.0 to 2.3 times that of NH listeners and increased with degree of hearing loss at 1.0 kHz. For a given SL of probe, SL of masker required to mask probe was similar for NH and HI listeners |
| Nelson & Pavlov (1989) | Forward Masking | 1.0 kHz; 20 msec; levels in range of 6-9 dB SL | 1.0, 0.9, and 1.1 kHz; 200 msec | No | Unknown | For NH listeners, slopes of masking functions more shallow for off-frequency compared to on-frequency maskers; for HI listeners slopes were dependent on amount of hearing loss at 1.0 kHz. Listeners with mild loss had slopes similar to NH; listeners with moderate loss showed similar slopes for off- and on-frequency maskers |
| Nelson et al. (2001) | Forward Masking | 1.0 kHz; 20 msec; 10 dB SL | 1.0 kHz; 10 other frequencies in range of 0.5- 1.2 kHz; 200 msec | No | Unknown | NH listeners exhibited shallower slopes for off-frequency maskers compared to the 1.0 kHz masker. For HI listener, slopes of masking functions were similar across masker frequencies |
| Plack et al. (2004) | Forward Masking | 4.0 kHz; 8 msec; 10 dB SL | 4.0 and 2.2 kHz; 204 msec | No | 16 NH: 19-37 9 HI: 54-68 |
Slopes of off-frequency masking functions more shallow in HI than NH listeners. Difference in masking levels required to mask probe for on-frequency versus off-frequency masker decreased with increase in delay time for NH listeners. For HI listeners, this difference decreased with increase of hearing loss |
| Lopez-Poveda et al. (2004, 2005) | Forward Masking | 0.5, 1.0, 2.0, 4.0, and 8.0 kHz; 10 msec; 10 or 14 dB SL | 0.5, 0.6, 0.7, 0.9, 1.05, 1.1, and 1.2 times the frequency of probe; 110 msec | No | 3 NH: 22-31 3 HI: 24-70 |
Slopes of temporal masking functions of HI listeners more shallow than those of NH listeners by a factor of 1.5 to 4 for both on- and off-frequency maskers at each of the probe frequencies. |
| Rosengard et al. (2005) | Forward Masking | 1.0, 2.0 and 4.0 kHz; 2.5 or 5.0 msec ramp; 10 dB SL for NH; 5 dB SL for HI | 1.0 and 0.55 times the frequency of probe; 100 msec | No | 5 NH: 18-32 5 HI: 27-74 |
For NH listeners, slopes of temporal masking functions were always more shallow for off-frequency compared to on-frequency maskers; for HI listeners, slopes of on- and off-frequency maskers were more similar but were highly variable across subjects. |
| Stainsby & Moore (2006) | Forward Masking | 0.5, 1.0, 2.0, 4.0, 6.0 kHz; 10 msec; 10 dB SL | 0.5, 0.8, 1.0, 1.15, and 1.3 times the frequency of the probe; 200 msec | No | NH: none 3 HI: 52-88 |
For HI listeners, all temporal masking functions were well fit by straight lines; for a given probe frequency, slopes were similar across different masker frequencies; slopes decreased with increasing frequency of the probe |
| Grose and Hall (1996a) | Comodulation masking release | 1.125 kHz; 400 msec | 7 comodulated 20-Hz noisebands at odd harmonics of 125 Hz; 600 msec; equal SPL and SL | No | 10 NH: 20-39 10 HI: 39-57 |
Maximum release of masking was 15 dB for NH and 10 dB for HI |
| Bacon and Takahashi (1992) | Overshoot | 1.0 and 4.0 kHz; 10 msec | Wideband noise; 400 msec; 3 spectrum levels of noise | No | 4NH: 20-34 5HI: 24-63 |
At 1 kHz, magnitude of overshoot similar for NH and HI, ranging from 0 to 15 dB across listeners; at 4 kHz, larger overshoot for NH (7 to 26 dB) than for HI (0 to 10 dB) |
| Strickland and Krishnan (2005) | Overshoot | 3.0, 4.0, 6.0 kHz; 10 msec; equal SPL | Broadband noise; 400 msec | No | NH: None 8 HI: 30-73 |
Amount of overshoot decreased with increase in hearing loss at test frequency; for hearing loss of 20-55 dB, overshoot was 5-15 dB compared to overshoot of 12-28 dB for NH listeners tested by Strickland (2001) for equal-SPL signals |