Can you clean baby's ears?

If younger than 1yr - better don’t touch their ears as they are still developing. (Some of 0-12 months babies were found that their listening skill is not good as usual by observing their movement/reaction/eye-contact/screaming .etc) - so it will be great to not touching inside but clean the outside area with clean water ***I did help my younger brother clean his ears deeply when he’s 3 years old to 7/8 years old since our family doctor told us he got “hardened cerumen” - need regularly clean it with proper process