Adapted White Noise versus Notched White Noise Differences of Minimum Masking Level and Residual Inhibition Emmanuel Coulon, Philippe Lurquin, Marie Paule Thill, Jérôme Lechien Departement of Otology, CHU Saint Pierre, Bruxelles, Belgium Introduction When helping tinnitus patients, many therapeutic noises can be used. In this study, we intend to compare two of these specific noises using Minimum Masking Levels (MML) and Residual Inhibition (RI). Adapted White Noise (AWN): Developed by P. Jastreboff White Noise adapted to the patient’s hearing loss Based on neuronal adaptation and homeostatic plasticity Notched White Noise (NWN, or Windowed White Noise) : Studied by C. Pantev Adapted White Noise with one octave removed around the tinnitus frequency Based on lateral inhibition Fig 1a : AWN Spectrum Fig 1b : NWN Spectrum Methods Subjects: 26 patients (14 men, 12 women) On average, mild hearing loss (R: 25dB HL, L: 23dB HL) Measures performed with adapted white noise and notched white noise: Loudness and frequency pitch matching Minimum masking level (MML) Residual inhibition (RI) Changes of tinnitus related distress during residual inhibition Results Significant difference between both therapeutic noises in favor of the adapted white noise (Manova Test – F(3,23)=3,80, p<0,05) Difference between both MML (t25 = -2,63 , p ≤ 0.05 – Fig 2) Difference between both changes of tinnitus related distress (t25 = 1,712 ; p ≤ 0.1 – Fig 3) No difference between both RI (t25 = -0,979 , p > 0.05) Weaker effect of both therapeutic noises for high frequency tinnitus(Fig 4) Conclusion Based on our results, the adapted white noise seems more efficient mainly with regard to the MML. Nevertheless, it is impossible, based on clinical measurements of tinnitus, to foresee the eventual efficiency of one of the two noises in the scope of a long term sound therapy.