Simple Q&A D&D 3.5 (by RAW) XXI

[Duke of Urrel]

Q 1035

Ghost Sound tells us it enhances Silent Image, how so and by how much?

A 1035

The Ghost Sound spell can't produce intelligible speech, following the rule that Figments generally can't unless their spell description says otherwise.

From this it follows that the Ghost Sound spell can add any sound effect to the Silent Image spell that is not intelligible speech and that otherwise falls within the volume requirements of the spell. So in the area where the Ghost Sound's area of effect and the Silent Image's area of effect overlap, you can create "enhanced" Figments that are both visible and audible.

Following the rules of Figments further, we could say that a more realistic Silent Image – with sound effects added – is less likely to seem suspicious, so that observers are less likely to interact with it and make Will saves against it.