Some extra pronunciation info, feel free to ignore if it looks boring
In the phonetic alphabet, liseuse is transcribed as [lizØ:z]
I think everything must be obvious except Ø and maybe :
: is used to lengthen the preceding sound, in this case Ø
Now Ø is the tricky part.
Wikipedia gives several examples of its uses, but it doesn't seem to come up in english. I'd say it's something like a lengthened uh sound.