writen text versus speaking the text

I am at lesson 10.1.  I have a hard time to swallow the sentence below.  The text is perfectly clear to me.  
et nous allons vous montrer comment cela se passe en français.
But the lovely female voice speaks to me what I distinctly perceive as
et nous allons vous montrer comment ça se passe en français.
there is no trace of "la" in cela.
So, if the female speaker does say cela se passe, how does the listener know?

Please enlighten.

I agree with you. It sounds like "ça se passe". :) I guess in context, it doesn't really change the meaning.

Hi all - I agree! I am not sure how that slipped through the cracks but it is changed now.

Bonjour,
I am having the same issue, but from a different angle. I am only at level one, module 4, but need some advice on how to tackle what is now becoming real french in terms of its use with all the tenses of the verbs, yes, no, never, etc. My problem is that to see the sentence it all makes sense and I can get the verb tense, etc. Hearing it, however, is now a complete disaster - the sentence sounds like one long run on word of which I have little clue of the meaning (can catch a few words). Anyway, is this a common struggle, do you just repeat 100 times if need be and literally memorize (which seems to defeat the idea of understanding basic structure so you can create endless new sentences) or..........? Any advice is greatly appreciated. Merci. 

Hi Paul - Hearing and understanding a new language is a common issue for a lot of people. One way that I have used successfully in the past is to listen to an online French radio station at work. It may take a few months but gradually the sentences do become easier to understand! For a more active way of doing it, you could watch French movies or sit-coms on Youtube.