In 'कविताएँ सुनी-सुनायी जाएँ' (Poems should be heard and recited), the verb is—

The form 'सुनायी जाएँ' (be made to hear/recited) is the causative form of the verb 'सुनना' (to hear). When the doer causes someone else to perform the action, the verb becomes prerṇārthak (causative). 'सुनना' becomes 'सुनाना' which is the causative/prerṇārthak form. Hence the verb in this construction is causative.