1. BUCNI Meeting BUCNI Meeting Aug. 28 2008 Effects of spectral detail and tonal variation on speech intelligibility Kyong, Scott, Eisner and Rosen

2. 2 Rationale Languages differ in acoustic features they employ; How much is tonal variation worth in terms of intelligibility and will this be reflected accordingly in the neural representation? Pitch employed activations dominantly in the right (Scott et al., 2000). Increasing intelligibility with increased spectral variation correlates with the activities in the left STS and the IFG

3. 3 Behavioural results Fig.1 A logistic regression model comparing the coefficient for tonal variation to that for spectral detail 1 2 3 4 5 6 8 16 (in number of channels) 2 4 6 8 (in number of channels)

4. 4 Proposed scanning design 12-14 Native speakers of English, right-handed without speech/hearing problem Factorial (3 x 2) + controls (2) or + 1 (mini block of silence) 3 different spectral variations (2, 4, 6) 2 pitch conditions (natural/flat pitch variation) 2 controls for complex acoustic spectral variations (2, 6; ½ with and without tone) Sparse sampling with 8 s TR Stimulus ~1.8 sVolume acquisition 3 s We expect to see the effect of intelligibility know if increasing intelligibility with tonal variations uses the same neural substrates – main effect of tone examine different contributions of spectral and tonal variations confirm that potentially, reduced clarity invites IFG involvement Thank you very much