Table 1.
Summary of studies of gap-detection thresholds (GDTs) 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-A. The second column describes the test stimuli. The third 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 fourth 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 fifth column provides information about the stimulus levels that were used to make comparisons among the groups (e.g., equal SPL or equal SL). The final column summarizes key comparisons of NH and HI performance.
| Study | Stimulus | Thresh. Match? | No. and Ages (Years)of Ss | Level Comparisons | Summary of Findings |
|---|---|---|---|---|---|
| Florentine & Buus (1984) | Broadband noise | NM | 6NH: 20-50 7HI: 20-57 |
Simultaneously equal SPL and equal SL | HI GDTs generally well-produced in most NMNH listeners; exceptions in two flat-loss subjects. |
| Buss et al. (1998) | 100-Hz noise bands | NM (approx.) | 3 NH: X̄ =31 7 HI: X̄ =47 |
Simultaneously equal SPL and equal SL (approx.) | At equal SPL, GDTs were equivalent for HI and NMNH; at equal SL, HI had larger thresholds than NMNH |
| Fitzgibbons & Wightman (1982) | Octave noise bands | No | 5 NH: X̄ =27 5 HI: X̄ =28 |
Equal SPL or equal SL | GDTs more similar for HI and NH at equal SL than at equal SPL |
| De Filippo & Snell (1986) | 50-Hz noise bands | No | 5 NH: 19-25 5 HI: 19-25 |
Equal SPL or equal SL | At equal SL and at equal SPL, HI had larger GDTs than NH |
| Glasberg et al. (1987) | Bandpass noises | No | 9 NH: 42-72 8 HI: 18-69 |
Equal SPL or equal SL | NH data were obtained on the normal ear of HI listeners with unilateral loss; GDTs similar for bilateral and unilateral loss subjects; GDTs for NH and HI more similar at equal SL than at equal SPL |
| Moore & Glasberg (1988) | Pure tones; narrowband noise | No | 7 NH: 45-72 7 HI: 45-72 |
Equal SPL and equal SL | Compared normal and impaired ears of unilateral-loss subjects; GDTs quite similar for equal SL comparisons |
| Moore et al. 1989 | 1 kHz pure tone | No | 2 NH: 21 4 HI: 56-72 |
Equal SPL | GDTs for HI listeners were roughly 1 to 2 times larger than those of NH listeners |
| Hall et al. (1998) | Bandpass noise | No | 25 NH: X̄ =30 21 HI: X̄ =49 |
Equal SPL | Mean GDTs of HI were roughly 1.2 to 1.7 times larger than those of NH subjects, but with considerable overlap in thresholds |
| Grose & Hall (1996b) | Sequences of 75-msec pure tones | No | 10 NH: 20-39 12 HI: 39-57 |
Equal SPL | Mixed results – HI and NH GDTs were comparable in simple stimulus conditions, with HI GDTs 1.1 to 2 times larger with complex stimulus markers |
| Moore et al. (1992) | Pure tones | No | 11 NH: X̄ =76 11 HI : X̄ =76 |
Equal SPL or equal SL | Elderly NH and HI had similar GDTs, which were larger than those of young NH listeners |
| Roberts & Lister (2004) | Broadband noise | No | 8 NH: 20-32 8 NH: 53-74 8 HI: 57-76 |
Equal SL | No significant difference in GDTs for elderly NH, elderly HI, and young NH |
| Lister & Roberts (2005) | 1/4-octave noise bands | No | 8 NH: 20-32 8 NH: 53-74 8 HI: 57-78 |
Equal SL | GDTs of elderly NH and elderly HI were similar and larger than those of young NH listeners |