Modeling intra-speaker pitch range variation: predicting F/sub 0/ targets when "speaking up"

We study F0 variation produced by "speaking up", as part of a larger study of pitch range variation within and across speakers (D.R. Ladd and J. Terken, 1995). We provide a function to predict target F0 values in this "raised" mode from F0 values at corresponding locations in speech produced in a neutral mode. Targets were F0 measurements at points of low internal variability in read Dutch sentences produced by 15 speakers. Across speakers, the relationship between normal and raised targets was well fit by an additive multiplicative function. The offset for this function was set to a speaker specific measured value. In the transformed space, the free parameters can be interpreted as: (1) an upward shift in F0, and (2) a multiplier affecting the size of F0 excursions. Parameter values varied independently across speakers, suggesting that individuals use different strategies when speaking up. We conclude that at least three speaker specific values (offset, shift factor, and multiplier) are required for pitch range scaling in this domain.