Differences in sensation level between the Widex Soundtracker and two real-ear analyzers.

BACKGROUND SoundTracker is an algorithm in Widex's Compass fitting software that could potentially be used to estimate a patient's aided sensation level (SL). SoundTracker's accuracy of estimating a patient's SL has never been verified in comparison to SL measured with commercially available real-ear analyzers. PURPOSE Determine whether statistically significant differences are present between the estimated SL of the Widex SoundTracker software application and the measured SL of the Audioscan Verifit and Frye 6500 real-ear analyzers at 500, 1000, 2000, and 4000 Hz. RESEARCH DESIGN This study used a randomized repeated measures design to determine differences in SL between SoundTracker and the Verifit and 6500. STUDY SAMPLE Ten subjects (N = 20 ears) were recruited who were experienced users of behind-the-ear hearing aids with conventional vented earmolds and had bilateral sensorineural hearing loss that was >30 dB HL below 1000 Hz and ≤70 dB HL to 4000 Hz. DATA COLLECTION AND ANALYSIS Real-ear in-situ thresholds (dB sound pressure level [SPL]) and real-ear aided responses (REAR; dB SPL) were measured at 500, 1000, 2000, and 4000 Hz to determine differences in SL between SoundTracker, Verifit, and 6500. A three-factor repeated measures analysis of variance (ANOVA) was utilized to determine differences between method (real-ear analyzers and SoundTracker), analyzer (Verifit and 6500), and frequency (500, 1000, 2000, and 4000 Hz). RESULTS Mean differences in measured SL for the Verifit and 6500 were ≤2 dB when compared to the estimated SL using SoundTracker. A statistically significant difference in SL was present between the Verifit and SoundTracker at 2000 Hz (p < 0.01), but no significant differences were present at 500, 1000, and 4000 Hz. A statistically significant difference in SL was present between the 6500 and SoundTracker at 4000 Hz (p < 0.01), but no significant differences were present at 500, 1000, and 2000 Hz. Mean differences in measured SL between the real-ear analyzers (difference of SoundTracker SL minus Verifit SL compared to the difference of SoundTracker SL minus 6500 SL) were ≤2 dB with a statistically significant difference present at 2000 Hz (p < 0.01), but no statistically significant differences were present at 500, 1000, or 4000 Hz. CONCLUSIONS Nearly 85% of the differences between the estimated SoundTracker SL and the measured SLs of the Verifit and 6500 were ≤2 dB. Despite some limitations of this study, SoundTracker could be useful as a counseling tool to illustrate to patients which sounds are audible or inaudible when unaided and aided.