highly significantp value < 0.001
The differences in means showed that phone-recorded audio samples displayed (a) highly significant lower values for formants F3 (difference = − 829; p value < 0.001) and F4 (difference = − 1020; p value < 0.001) and (b) significant higher shim% value (difference = + 2.73; p value < 0.05) and shim apq5 value (difference = + 1.60; p value < 0.05).