Table 5. Calculated 90% reference intervals from the archival literature.
Reference intervals based on SEM across trials in adults have been previously published (Reavis et al. 2015). Here we show reference intervals for 3 of the studies reported by Reavis et al. (the one with the longest test-retest interval and the two with the largest samples). Results are also shown for studies not included in Reavis because they reported only the average test-retest difference. This allows comparison with 2 additional studies conducted in adults as well as 3 studies in children as young as age 3 years. Larger reference intervals are observed at high frequencies and possibly for longer baseline to follow-up times. Variability in studies of children is at the upper range of adults even though infants and toddlers were not tested.
| Author | Mean Age (Range) yrs | Sample Size | F2 kHz | L1/L2 dB SPL | Follow-up Interval | SEM | MeanShift (SD) | 90% reference interval |
|---|---|---|---|---|---|---|---|---|
| ‡Franklin et al 1992 | 30 (19–44) | 12 | 1000–8000 | 65/65 | 4 weeks | 1.17 to 2.3 | 2.72 to 5.35 | |
| Roede et al 1993 | 26 | 12 | 1000–8000 | 55/55 | 6 weeks | 2.9 (2.7) | 7.34 | |
| 70/70 | 1.8 (1.8) | 4.76 | ||||||
| ‡Beattie et al 2003 | 24 (19–27) | 50 | 1000–4000 | 65/65 | 5–10 days | 2.5 | 5.82 | |
| ‡ Ng & McPherson 2005 | 23 (19–35) | 35 | 1000–6000 | 70/70 | 20 min-15 days | 2.64 | 6.14 | |
| 7000 | 3.04 | 7.07 | ||||||
| Dreisbach et al 2006 | 22 (18–29) | 25 | 2000–8000 | 60/45; 60/50; 70/55 | 4–8 weeks | 2.8 (2.7) | 7.24 | |
| 10000–16000 | 5.15 (4.4) | 12.39 | ||||||
| Sockalingam et al 2007 | 9 (5–12) | 24 | 2500–7000 | 65/55 | 13–15 days | 0.52 (2.87) to −1.57 (4.62) | 5.24 to 6.03 | |
| 10000 | −0.56 (5.57) | 8.60 | ||||||
| *Conrad & Dreisbach 2011 | 4.7 (3–6) | 30 | 1000–6000 | 65/50 | 54 (7–277) days | 0.2 (4.63) | 7.82 | |
| 7000–16000 | −0.11 (6.02) | 9.79 | ||||||
| *Newman & Dreisbach 2012 | 10.7 (10–12) | 37 | 1000–6000 | 65/50 | 51 (7–460) days | −0.35 (4.88) | 7.68 | |
| 7000–16000 | 0.14 (5.31) | 8.59 | ||||||
The 90% reference interval calculated from SEM or average difference between trials and standard deviation: +/−1.645*sqrt2*SEM OR meanshift +/− 1.645*SD
These studies represent 3 of the 10 included in Reavis et al. 2015 meta-analysis. Readers can refer to that study for data on the remaining 7 adult studies.
Studies were conducted using depth-compensated in-the-ear calibration.