Cockatiel hatching time

Question
Hey again, thanks for telling me and I rated you. I have also read that their will be peeping sounds coming from the eggs, 24-72 hours before hatching. Could you tell me how that sound would sound like?
-------------------------------------------
The text above is a follow-up to ...

-----Question-----
Hey Chris, you know how I told you that the first egg and the second egg started getting incubated on Dec, 1st. Well, they started getting incubated since Nov 29, I candled the first egg yesterday (it's 16th day of incubation)at around 9:00pm and there was a dark spot which was covering about 70% of the egg and a white part which was covering about 30%. When can I expect hatching?
-----Answer-----
Hi, Aamir.

They should start hatching around 18 December...3 more days!

Chrys

Answer
Hi again, Aamir.

It takes a baby bird 24-48 hours to hatch out of an egg.  They start pipping on the inside first, all the way around the egg.  Once this is finished, they start on the outside.  This is when you should be able to start seeing a hole on the outside of the egg shell.  You might be able to hear peeping sounds if you hold your ear close to the egg, however, you should not be picking up any eggs this close to hatching time.  The babies are getting in position to hatch and if they are not in the correct position, they can't pip the egg shell nor hatch out.  Just leave the eggs alone so they can hatch.  I can't describe the peeping sound in writing...it's like what you might hear from a baby chicken, but it's so faint, I've only heard this sound myself a few times in over 17 years.

Chrys