Table 1.
Study and participant characteristics.
| Methods | Auditory training 1 Ferguson et al. (2014) |
Auditory training 2 Henshaw and Ferguson (2014) |
Working memory training Henshaw and Ferguson (2013b) |
|---|---|---|---|
| Study design | Randomized controlled trial | Repeated measures | Randomized controlled trial |
| Intervention | Phoneme discrimination in quiet 11 phoneme continua Phonomena/IHR STAR |
Phoneme discrimination in multitalker babble 11 phoneme continua Phonomena/IHR Star |
Verbal and Visuospatial working memory and storage tasks Cogmed RM |
| Intervention duration requested | 360 min (6 h) across 4 weeks 15 min/day, 6 days/week (total = 24 sessions) Immediate Trained (IT): weeks 1–4 Delayed Training (DT): weeks 5–8 |
210 min (3.5 h) across 1 week (7 days), 2 × 15 min/day (total = 14 sessions) | Approximately 990 min (16.5 h) across 5 weeks, 35–45 min sessions/day, 5 days/week (total = 25 sessions) |
| Retention period | 4 weeks post-training: IT: weeks 4–8 DT: weeks 8–12 |
None | 6 months post-training |
| Control activity | None | None | Active control working memory tasks – span fixed at 3 |
| Control period: duration | DT: T1–T2 = 4 weeks | T1–T2 = 1 week | T2–T3 = 5 weeks |
| Test–retest period | DT: T1–T2 = 4 weeks | T1–T2 = 1 week | T1–T2 = 1 week |
| n participants (n females) | 44 (15) | 30 (10) | 57 (30) |
| Participants (source of recruitment) | Non-HA users, mild hearing loss (general practitioner) | Existing HA users, mild-moderate hearing loss (volunteer database) | Existing HA users, mild-moderate hearing loss (volunteer database) |
| Mean age in years (SD) | 65.3 (5.7) | 67.4 (7.1) | 64.9 (6.0) |
| Mean BEA0.5-4kHz (SD) dB HL | 32.5 (6.0) | 43.6 (13.6) | 44.0 (13.8) |
IT, immediate trained; DT, delayed trained; HA, hearing aid; BEA, better-ear average; min, minute; T1–T2, time period between the first two test sessions to measure test–retest effects.