In the books, the battle plays out a little different...
Regarding your question in particular:
First, there's a dike "two furlongs below Helm's Gate" that they indeed try to use to harass/slow down Saruman's army, but with little effect as it is only lightly manned and supplied:
A slow time passed. Far down in the valley scattered fires still burned. The hosts of Isengard were advancing in silence now. Their torches could be seen winding up the coomb in many lines.
Suddenly from the Dike yells and screams, and the fierce battle-cries of men broke out. Flaming brands appeared over the brink and clustered thickly at the breach. Then they scattered and vanished. Men came galloping back over the field and up the ramp to the gate of the Hornburg. The rearguard of the Westfolders had been driven in.
'The enemy is at hand!' they said. 'We loosed every arrow that we had, and filled the Dike with Orcs. But it will not halt them long. Already they are scaling the bank at many points, thick as marching ants. But we have taught them not to carry torches.'
Also, the night is pitch black and neither side has good vision on the other... but it's actually the Men that make some psychological use of that:
It was now past midnight. The sky was utterly dark, and the stillness of the heavy air foreboded storm. [...] Arrows thick as the rain came whistling over the battlements, and fell clinking and glancing on the stones. Some found a mark. The assault on Helm's Deep had begun, but no sound or challenge was heard within; no answering arrows came.
The assailing hosts halted, foiled by the silent menace of rock and wall.
It's only then that the Orcs start doing their "battle chant" (hey, they need some courage, too), and finally the defenders start shooting back.
tl;dr: The Men did harass the approaching army on its way, but ran out of ammo. Then they played dead for a bit to confuse the Orcs and because it was too dark to waste their limited amount of arrows yet anyways.
PS: Elves of Lothlorien being present at the battle is just something out of Peter Jackson's head.
