Table 2.
Review of studies using dual-microphones ones (sec text for details).
| Study (Type of Aid) | Subjects | Signal/Level/Azimuth | Noise/Level/Azimuth | Dual-Mic Advantage |
|---|---|---|---|---|
| Valente et al (1995) (BTE) | 50 adults Mild to mod-severe |
HINT sentences at 0 azimuth | HINT noise at 65 dBA at 180 azimuth | 7.4–7.8 dB for “basic” 7.7–8.5 dB for “party” |
| Lurquin et al (1996) (BTE) | 18 adults Mild to mod-severe |
Bisyllabic word list at 0 azimuth | Cocktail noise adjusted to 50% correct at 180 azimuth | 6.6 dB |
| Voss (1997) (BTE) | 13 adults Mild to mod-severe |
Danatale monoxyllabic words at 0 azimuth | Babble noise at 45, 135, 225, 315 azimuth at SNR of 0, −10 and −15dB | 2% at 0 dB SNR 16% at −10 dB SNR 30% at −15 dB SNR |
| Agnew et al (1997) (BTE) | 20 adults Mild to mod-severe |
HINT sentences at 0 azimuth | HINT noise at 65 dBA at 180 azimuth | 7.5 dB |
| Preves et al (1997) (ITE) | 10 adults Mild to mod-severe |
HINT sentences at 0 azimuth | HINT noise at 65 dB SPL at 115 and 245 azimuth | ∼3.0 dB for unequalized ∼2.5 dB for equalized |
| Gravel et al (1999) (BTE) | 10 young (4–6 yrs) 10 old (7–11 yrs) Mild to mod-severe |
Pediatric Speech Intelligibility at 0 azimuth at 50 dB HL | Multi-talker babble at 180 azimuth varied in 2 dB steps | young: 4.6 dB for words 5.1 dB for sentences old: 5.3 dB for words 4.2 dB for sentences |
| Larsen (reported in May, 1998) (BTE) | 19 adults Mild to mod-severe |
Danatale monosyllabic words at 0 azimuth | ICRA noisc at 45, 135, 225 and 315 azimuth | 3.6 dB re: performance of omnidirectional BTE w/DSP |
| Ricketts/Dhar (1999) (BTE) | 12 adults Mild to mod-severe |
HINT sentences at 0 azimuth (.6 msec reverb) HINT sentences at 0 azimuth (anechoic) | HINT noise at 65 dBA at 90, 135, 180, 225 and 270 HINT noise at 65 dBA at 90, 135, 180, 225 and 270 |
Senso C9 (directional/digital) = 4.5 dB Phonak AZ (dual/analog) = 6.5 dB Siemens Prisma (dual/digilal) = 5.0 dB Senso C9 (directional/digital) = 6.5 dB Phonak AZ (dual/analog) = 7.5 dB Siemens Prisma (dual/digital) = 6.0 dB |
| Pumford et al (1999) (ITE and BTE) | 24 adults Mild to mod-severe |
HINT sentences at 0 azimuth (anechoic) | HINT noise at 65 dBA at 72, 144, 216 and 288 azimuth | ITE = 3.27 dB BTE = 5.77 dB |