Here is a very comprehensive list taken from a post here.
I lifted the link from here posted way back in January. I hope this helps.
Here is my list of sound changes. This is all in reference to changes made to the original film, except in a few instances I've pointed out differences also from the 1993 re-mix. Some of these new sounds obviously were heard in the 1997 re-mix, some are new to this mix. I've also included a few picture changes, but I feel they have been covered everywhere, while the sound mix has been virtually ignored. I have not noted any changes to specific SE shots (such as the destruction of Alderaan) since these shots are entirely new.
The 1954 recording of the Fox logo is still played though it sounds very distorted.
The new Lucasfilm logo is shown.
The ?Star Wars? title card starts moving much too fast in relation to the original and can be seen ?shifting gears? as it gets smaller and slows down.
New explosions can be heard over the opening shot.
The foley in this mix is very loud and in your face. Not subtle in anyway. Note Threepios footsteps. They've always been there, just never this loud.
The sound of the ship docking has some revised sound.
The shirts of the rebel troopers change colors. They were always gray before. In some shots now they are blue.
Vaders voice has been re-processed throughout the entire film to get him to match the sequels.
When Artoo opens the door to the escape pod, the button he pushes buzzes.
The laser blast that convinces Threepio to get in the escape pod was re-done in 1993. It is the same sound effect as a lamp blowing up in Raiders of the Lost Ark. This effect is also heard later in the movie.
When Vader is talking to the ?Second Commander? (?Lord Vader, the battle station plans are not aboard this ship!?) the room in the background makes beeping noises. For fun, I?ll point out that this actor has the same voice as General Dodonna at the end of the movie. I suspect that the ?Second Commander? is dubbed.
When Artoo is shot by the Jawas and falls over a tremendous bass impact has been mixed in.
The restraining bolt being installed makes a different sound.
Artoos arrival inside the sand crawler makes a new sound.
You now hear the sand crawler start up as it starts to move.
Later, you hear the sand crawler come to a stop. Threepio then says, ?We?ve stopped? before telling Artoo to wake up.
The sound of Threepio rising from the oil bath has been augmented.
The lunch scene with Beru and Owen has some new foley (Beru?s chair makes a sound now). This is a quiet scene and you can literally hear the faders being brought down after every line of dialogue. Dailogue does not sound integrated in this scene.
Beru?s pronunciation of ?father? has been re--done......again.
Luke?s land speeder can be seen in the long shot from the sand peoples point of view. Previously it was just a white speck moving.
The clanking of the sand persons gaffi stick is heard in this mix.
The Krayt Dragon sound that Ben uses to scare the sand people has been re-done. It almost sounds like a police siren at first. Definitely sounds artifical as opposed to the older, more organic sound.
The light sabers have not been re-processed to match the sound heard in the prequels.
In this mix it?s very clear that the bartender has been dubbed. It was not as obvious before.
When Luke is thrown into the table, it makes an all new sound effect.
When the stormtroopers walk into the bar they can be heard saying, ?Undertand you had some trouble in here?. This is heard under Hans, ?Looks like somebody?s beginning to take an interest in your handiwork.? line.
Alien sound effect is missing just before Threepios line, ?I would much rather have gone with Master Luke than stay here with you.?
The music edit just after the Jabba scene is pretty bad. The music just starts. Also Bens line ?If the ships as fast as he?s boasting we ought to do well? is different than the original mix. It sounds edited together here.
A quick dissolve is missing between the shot of the spy and the interior entrance of Docking Bay 94. It is a hard cut now.
The spy makes some more sounds before informing the stormtroopers of where Luke and Ben are.
There are new explosion sound effects in the shoot out in Docking Bay 94.
?You would prefer another target? A military target?? both sound crystal clear. ?Then name the system!? is clearly from the old mix. Right in the middle of the line there is a quality shift. This happens through out the entire movie, but this may be the most obvious. It almost feels like a game, wondering if the next line is going to be the new clear dialogue or the older sounding dialogue. Obviously, there is a lack of consistency here and it?s jarring throughout the film. This is problably the worst feature of this new mix.
When the Falcon arrives at Alderaan there is some very deep bass. However, when the Falcon is captured by the Death Stars tractor beam, deep bass is missing that was heard in the 1993 mix. However there is a lot of sound of the cockpit shaking.
Also in the 1993 mix, the sound of the TIE fighter shooting at the Falcon could be heard. That?s not here nor was it in the original mix.
The PA systems line, ?Close all outboard shields? sounds different.
Just before Han and company come out of the secret compartments, the two inspecting stormtroopers stop at the exit ramp and one of them says, ?There?s no one here.?.
When Luke exits out of the Falcon and taps his stormtrooper helmet, static can be heard.
The dialogue keeps changing during the command office scene, between the clear dialogue and the older sounding dialogue.
The computer in the detention block scene makes new noises.
When Han, Luke and Chewie are shooting the cameras in the cell block area, the explosions are all re-done. There is also some new blaster fire added. When Han shoots the console, his blaster is much louder now then it was before.
The explosion as the stormtroopers blast into the cell block is much louder and has more bass.
When Leia shoots the hatch to get into the garbage chute, the explosion is different.
Chewie pounding on the door of the trash compactor makes new sounds.
The famous blooper of the stormtrooper walking into the door has now been punctuated with a loud ?clunk? sound effect. What was once a tough to see mistake is now pointed ot for everyone to see.
When Ben is turning off the tractor beam (I guess this is what he?s doing since the display is no longer in English) some sound effects that were heard at Bespin in The Empire Strikes Back and in ALIEN are mixed in here.
The creature sound effects after they get out of the trash compactor are different.
When Leia fires her blaster during the chasm crossfire, it no longer sounds like Dirty Harry?s .44 magnum. This chasm also has the ALIEN/Bespin sound effect.
When Luke throws the grappling hook, it makes a ?whizzing through the air? sound effect.
When they are shouting for Luke to come on board the Falcon (after Ben?s death) Leia now says, ?Luke, come on!?. Previously, it was just ?Come on!?.
Music reverb heard during the fight with the TIE Fighters is gone.
During the TIE Fighter fight, there is a long shot of the Falcon and you can see red blaster fire coming from it. There is now sound there to match.
During the first dive towards the attack on the Death Star, key music has been dialled out for a few moments.
?He?s on your tail? line from the SE mix is not heard here.
New sounds can be heard in Red Leaders cockpit as his ship is failing.
When Red Leaders engine is hit by blaster fire, it now makes the same sound as a lamp blowing up in Raiders of the Lost Ark.
As Han, Luke, and Leia walk off after the battle, new crowd cheering effects can be heard.