It means that he does not attend or abide by what he hears or is ordered. That he does not accept what they tell him, that he disobeys. It is inflection of desoír that means not to abide, to disaspecting, not to attend not to listen.
Ignoring means when someone listens and understands what is said, but performs any action regardless of what they have heard and understood. It is the gerund of the verb Miss. Synonyms: ignore, pass.
Do not pay attention, do not follow advice or indication