Hi there!
I am an audio expert also in the field of audio restoration. First off, I would ask you, in case you consider my bid, to provide me the original file. For the sake of naturality I would remove noise and gate it from scratch. Whatever could be done with the file you attached won't feel entirely natural. The sound was likely captured in a natural environment with natural reverberation. That is lost if you gate the sound like that. I offer you a quick and professional job, and as I always do when it comes to restoration, which is a very tricky area where improvements can be done but not miracles, I will charge you only if the result works well.
Of course the normalizing and removal of "alien" sounds will be performed as well to its fullest possible without distorting or adding an artificial quality to the piece.
I invite you to check out my portfolio and profile to evaluate my skills, experience and reputation on the Freelancer.com community.
Don't hesitate to contact me through private message.
My best regards,
Diego
MediaSync