"More stonedeaf" is an expression used to describe someone who is even less likely to listen or respond to reason and advice than someone who is simply stonedeaf. Synonyms for this phrase could include "completely unresponsive," "wholly unyielding," and "utterly unresponsive to reason." Other words that could be used to describe such a person might include "obstinate," "intractable," or "immovable." People who are described as "more stonedeaf" may be seen as aloof or stubborn, or they may simply be too set in their ways to consider alternative or opposing viewpoints. Despite their lack of responsiveness, it's still possible to engage with them in conversation and work to find common ground.