hi , i am doing some training in zb, and tried to start with some zspheres, but near the end of the job, the ears remains without resolution (can´t sculpt smoothly and get very crunched ) , and the head is at level 7 ! please, can anyone help ? thanks very much
It looks like you could use some more topology there, try this:
1.take mesh to the lowest level- if that is the lowest shown, hide the 4 squares where the ear will be
2.In the Tool dropdown, open the Geometry menu, under the divide button press the Edge Loop button. It adds another loop to your mesh.
3.Unhide the hidden mesh. You can go back up through your subdivision levels now.
You may need to do some smoothing of there is a creasing effect. Also remember that this should be done early on if you can because it usually needs to be on the lowest subdivision level you can get away with.
Hope that helps,
Heather 
Hi Dirtrunner,
THANK YOU VERY MUCH MAN !!!
IT WORKS !! really thank you.
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i did some improves in other areas using the edge loop, and its amazing.
some screenshots :
the sculpt is working now… just doing some improvements, and voilá. i ´ll show the final result soon.
Best regards
Cool, glad it worked for you. That one comes in handy from time to time. 
_ Heather