Depends.
These motors dont deliver alot of volumn or pressure at idle, so if you mean you let it idle a long time, and then the noise gets louder, then it could have other problems.Or you could simply have the wrong oil in it...maybe someone used some 0w 40 oil. But as a rule the valve ticking isnt gonna get much louder, but should stay in time with engine rpm...

 

Main bearing/crank issue could get louder as the engine warms up.

I'd agree with what has already been posted... Change the oil to make sure it has the right grade/weight, check the valve adjustment, and get a 2nd opinion on the sound if it is still there.