When the subjects were speaking in a quiet room certain of their syllables hit clearly defined notes. Others, F3 and G3, were over-represented. But the peaks and troughs in the pitch variation of normal speech struck these notes, and not 'microtones' in between. The speakers were unconsciously arranging the tones of their voices on the pitch framework of the music they were used to hearing. F, G and A in the third octave and C, E F, G and A in the fourth.
Music does seem to leave a 'pitch imprint' in our minds.
When asked to sing favourite songs, many people do so within about a semitone of the original recording from which they learnt them. Indeed, some musicologists believe that song arose from sound patterns that have a particularly emotive effect.