Nicholas Royle & Shaun Jeffrey say “talk to yourself.”
Nicholas Royle: My tip is to read your work out loud. Never consider it done until you’ve read it out loud to yourself. You will catch all sorts of hidden problems – linguistic infelicities, awkward phrasing, unwanted repetition – that you will otherwise not notice. Read it slowly, out loud, with the proper enunciation, as if you were giving a public reading, and highlight problems as you go.
Shaun Jeffrey: Read your work aloud and it will allow you to spot things that don't sound right.
Dixon says - there are a few alternatives. It can be just as helpful to have someone else read your story to you. Maybe your local critique group would consider helping with that, or a writer friend you could swap services with.
Also, if you have a Kindle, you can send your work to that device from your computer. After it's downloaded, use the read-back feature. You have the choice of a male or female voice, and most folks find the male voice sounds more natural and conversational.