I do not understand the term resonating cough.
Since you say he was diagnosed with asthma
before, its likely that he has one such episode now. You have not mentioned any fever
, which too favours asthma.
Till you meet your pediatrician
, there is no harm in giving Albuterol
puffs in the same dosage recommended to you for the previous episode.
Do visit your doctor when its possible.
Hope you find my answer useful.