 He found his way around this entire problem by replacing /t/ and /k/ with the /p/, and /d/ and /ɡ/ with /b/ (which itself only differed in voicing from /p/).In the context of a familiar word, listeners often ignored the mispronunciation altogether (a phenomenon later explored by researchers in the field of cognitive science).Kempelen believed that people were more forgiving of the errors made by his machine due to the frequency of the reed and vocal tract resonant length he chose to use, which create a resonance much more like a young child, than that of an adult.