Silent Portal

The door squeaks slightly as you force it. You pause and wave your finger in a pattern along the opening and it silences.

(Spell Compendium, p. 190)
Originally posted on D&D tools

Illusion (Glamer)
Level: Sorcerer 0, Wizard 0, Assassin 1,
Components: S,
Casting Time: 1 standard action
Range: Close (25 ft. + 5 ft./2 levels)
Target: One portal
Duration: 1 minute/level (D)
Saving Throw: Will negates (object)
Spell Resistance: Yes (object)

This simple cantrip negates the sound of opening and closing a single portal (door, window, gate, drawer, chest lid, or the like). Even the squeakiest door opens without a sound when under the effect of this spell. Silent portal covers only the normal means of opening and closing the targeted portal. Breaking a window or kicking in a door still makes noise, but opening a door that is loosely hanging by its hinges does not (since this is the normal way a door would be opened). Portals composed of magical energy are not affected by this spell.

In the case of magic or even intelligent portals, Spell Resistance and a Will save (DC 10 + caster’s ability modifier + other modifiers as appropriate) apply.