The effects of multitalker and masker noise on fundamental frequency variability during spontaneous speech for children and adults.

Young adults (N:10) and children aged 5-10 yrs (14 M, 14 F) spoke spontaneously in quiet and in the presence of masking at 90 db SPL in binaural earphones, either white noise or multitalker noise. Fundamental frequency (fo) variability data (coefficients of variation) for the stressed and nonstressed words were submitted to ANOVA. Fo variability observed during the production of stressed words was significantly more variable than nonstressed words. Also, multitalker noise affected performance variability while white noise did not. Evidence supporting the operation of a mixed control strategy during speech production was discussed.