It sounds like [psi] In english, it sounds just like in the word "ps-ychology"

The Best Answer is: To pronounce "Ψ/ψ" sounds like a "Psi", in which you need to epmphasise in the last vowel -i. Alternatively, I would highly recommend this website in which you can clearly listen to the way we pronounce "Ψ/ψ" http://www.howjsay.com/index.php?word=psi Hope this might have helped!