This question was put to Shaykh Muhammad ibn ‘Uthaymeen (may Allaah have mercy on him) who said: 

(The pilgrim) cannot afford to stand there for long, rather he should face the Black Stone, point to it, say Takbeer and start walking. This is not a place where one should stand for any length of time, but I see some people standing there and saying, “I intend to perform tawaaf for the sake of Allaah, seven circuits, tawaaf of ‘Umrah, or a voluntary tawaaf,” and so on. This is based on a mistaken notion about the niyyah (intention). Speaking the intention of doing acts of worship out loud is an innovation. It was not narrated from the Prophet (peace and blessings of Allaah be upon him) or from any of his companions. You are performing an act of worship for the sake of Allaah, Who knows your intention, so there is no need to speak it out loud.