Here's why:
* Shy vowels are vowels that are pronounced with a reduced or weakened sound, often in unstressed syllables. They are typically represented by the symbol schwa (ə).
* In "doctor", the vowel sound is clear and strong, even though it's in a stressed syllable. The vowel sound is a short "o" sound, similar to the vowel sound in "hot" or "cot".
Therefore, the vowel sound in "doctor" is not a shy vowel.