Egg Not Hatching - Should I Be Concerned?

[_Featherian]

My chicken egg started making some noise this morning, but there’s still no seeable cracks on it until now (evening). When should I get concerned?

(The noise it is making is not often and not very loud)

 

[SilverBirds]

How many hours has it been since you heard the internal pip?

 

[_Featherian]

How many hours has it been since you heard the internal pip?

We could say 8-9 hours

 

[_Featherian]

I still hear it

 

[SilverBirds]

I'd give it 10 more hours to externally pip. If it doesn't make one in that time, I'd create a safety hole above the air sac.

 

[_Featherian]

Update
10 hours later, I come to check and see one small crack with the chick still alive, still not so noisy, inside.