Whether a hard lump in the earlobe will go away on its own will depend on the etiology that promotes the formation of that hard lump.
If the lump is caused by a sterile inflammatory lesion, it will usually clear up on its own within a short period of time.
If the lump is caused by a bacterial infection, passive elimination is more likely following intervention with the appropriate medication.
If that hard mass is already formed scar tissue, self elimination is less likely.