How to pronounce the “s” in “apples” in English and American English?

I remember my teacher told me the “s” in “apples” should be pronounced as /z/, but in some American teaching programs, I heard it be pronounced as /s/.

Which one is correct? Does it follow the same rule in English and American English?

Update:

Thanks for all the comments and answers.

I heard it from this free starfall math cource: http://more2.starfall.com/m/math/addResult-tennis/load.htm

There are three questions, and the things “balls”, “oranges”, “apples” are counted in each question. (The order may change every time)

For my ear, the “s” in all of the three words are all sound like /s/, not like /z/ (in zip)

Do I make a mistake?

Update: I just record how I read the 4 words apples, oranges, balls, bus/buzz, and uploaded it to this url: http://vocaroo.com/i/s12qqzMEwOYD . For each word, I read the s as /s/ first, then /z/ (from my understanding).

So there are 8 words:

1. apples /s/
2. apples /z/
3. oranges /s/
4. oranges /z/
5. balls /s/
6. balls /z/
7. bus /s/
8. buzz /z/

Could you tell me how do you feel?

Do you think it’s /s/ or /z/ for my reading of 1/3/5? Do you feel it strange the way I pronounce /z/ in my 2/4/6? And can you distinguish the 7 and 8 from my reading?

Update: Thanks so much for stangdon’s fantastic comment and the audio recording in that comment: http://vocaroo.com/i/s0nXNmyTOsVc