I hate doing this, but it feels like your advices get lost under the weight of 51 page long "your ideas" post. I am adding it here too, I believe it will be merged with it anyway in some time.

So here it goes:

No matter what we believe, it can't be denied that sound is very important in a thief game. The perfect use of sound had a huge part on the impact of the first game. Both in-game and in cutscenes. How can we forget the persuasive voice of Constantine? The music? The moaning of a zombie?

The technology has changed, however. I don't know if it was discussed before, but please consider the possible appliance of binaural sound recording technique.

For an example, please watch this, using your headset or earphones.This sound technique is way beyond stereo technology, and can be a real surprise the first time you hear it. If you don't know what this is, I guarantee that you will... be thrilled... especially when you think of it in a thief game.

http://www.youtube.com/watch?v=IUDTlvagjJA

When we use our real ears to hear sounds, our head and auricles bend and change the sounds. So when something drops to the ground on the left, the sound waves that come to your left ear is different than the sound waves that come to your right ear. This small difference in sound level and wave differences are interpreted by our brain and this gives us an estimation of the distance and place of the sound source.

Binaural technique is a special recording method. Basically, two high-tech microphones are placed in a sculptured human head, inside the ears - which are shaped exactly like ears. Then it is placed in the middle of the recording room. Every sound has a different wave on each microphone, and a special algorithm records the sound. As a result, when you use your headset to listen this sound, it feels extremely real. You can understand if the voice is coming from above or below your head level, close as 1 meter or far as 4 meters or whispered right into your ear.

Now consider this effect in thief 4.

Exciting, right?

However, it is very very diffıcult to do it in game. Becase the player is free to go anywhere, and the sound sources can change during the game according to the flow of that particular gameplay progression. There is no way of placing the mannequin head in everywhere possible in every combination. The only way to solve this would be to create a program that calculates all the variables in the change of placement of the soundsource, and modify the waves according to the players positioning in real-time game.

I believe we will have this technology someday, but it will be a long wait.

However, this technique can still be used in Thief4

-Possible -in game, game engine cutscenes where player loses control and is watching the game, probably during the beginning or ending of a mission. We all know how strong the story can get in a thief game, and this sound tech can enhance the experience of receiving the story.

-Introduction, between the mission cutscenes, ending movie : if we watch these from the perspective of Garret, this technique can be used. Imagine a cutscene where Garret is walking in a dark corrdior and suddenly a portcullis is shut behind him with a loud crank.

Maybe we see the full usage of this technique in thief 5