I'm sorry  there is no Hail Sting audiobook.  Being an independent author, I have to pay out-of-pocket to have it made and it's very expensive.  Maybe once HAIL has become  more popular, I'll have it narrated.  Until then, turn your friends onto HAIL so I can have enough $$$ to dazzle you with Hail Fire audio. Operatoin Hail Storm audiobook is free this month.