1. 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.