The direct filling gold segments can be compacted:
The gold segments can be compacted by hand pressure alone, by hand pressure combined with a hand mallet, or by a mechanical device  that is activated by a spring, pneumatic pressure, or electronically (using an electromallet). 
The direction of force application, the amount of applied pressure, and the compaction pattern are critically important factors controlling the quality of the gold restoration.

Ref:Phillip’s Science of Dental Materials ed 12 pg 414
By hand pressure alone
By hand pressure combined with a hand mallet
By using electromallet
All of the above