I have (FINALLY!) found this to be a very common problem. ALL PowerPC machines, when running Minecraft 1.4.2 or 1.4.4, play a scratchy, loud crackling sound when playing Minecraft. I am going to show you how you can fix this. (Me and my friend found this out while messing about with the minecraft.jar file btw.) I hope to make this as easy as possible. The instructions are fairly simple and short, they look long below because I have put in EVERY little detail. ****I WILL PROVIDE UPDATED INSTRUCTIONS TO MAKE THE MINECART SOUNDS WORK BECAUSE MOJANG HAVEN'T FIXED THE ISSUE YET, SO KEEP CHECKING THIS THREAD, I WILL UPDATE IT BY JANUARY. I am testing it to make sure 100% EVERY sound works!**** However the following is the current instructions! Step 1. Download the old Minecraft 1.3.2 jar file if you don't have a backup of it here: http://bit.ly/PVWHRK Step 2. Rename the old 1.3.2 jar from its current 'minecraft.jar' name to distinguish it from the 1.4.2 minecraft.jar. Step 3. Right-click the old 1.3.2 jar file and click open with, then Archive Utility. (If you don't see 'Archive Utility', click 'Other' and navigate to: Your Hard Drive (usually Macintosh HD), System, Library, CoreServices, and then Archive Utility.app) Step 4. There should now be a folder called 'minecraft'. Double-click it, and look for a folder called paulscode. (It may be hard to find since there are so many files inside the folder. Just keep looking until you find it.) This is a VERY important folder. Drag this folder to your desktop. Step 5. Once you have dragged paulscode to your desktop, (click on the finder icon in the dock if you don't have finder open), and at the top apple bar (with the apple logo, time, etc.) click on 'Go' and then click on 'Go to Folder...' then copy and paste this into the text box: ~/Library/Application Support/minecraft/bin/ Click Go. Step 6. You should see something called 'minecraft.jar', this is your current 1.4.2 Minecraft file. Right-click and click 'Open With', then Archive Utility. (Again, if you don't see 'Archive Utility', click 'Other' and navigate to: Your Hard Drive (usually Macintosh HD), System, Library, CoreServices, and then Archive Utility.app) Step 7. Delete the 'minecraft.jar' file. NOT the 'minecraft' folder. Step 8. You should see a folder called minecraft. Normal (left) click it ONCE and it should be highlighted blue. Then press the Enter key. You should now be able to rename the folder. THE FOLLOWING IS VERY IMPORTANT. Name it 'minecraft.jar', with a lowercase 'm'. Step 9. Double-click the 'minecraft.jar' folder. Inside there should be another paulscode folder. This is the problem. Delete it. And then drag the previous 1.3.2 paulscode folder, which should be on your desktop. Step 10. Close all your windows and open up Minecraft, and ALL the new sounds (INCLUDING the bats and all the other new Minecraft 1.4.2 sounds) should work! Enjoy! I hope to help you again in the future, and I am working to not be a MacRumors newbie anymore! Thanks! EDIT: ALSO WORKS ON 1.4.4 *A (brief) FIX FOR THE FOLLOWING IS BELOW! Some people may notice that when riding a Minecart with the sound turned up, Minecraft will crash. The easiest thing to do is to turn the volume all the way down to 0%. (not your Mac volume, the Minecraft volume. Press the esc key while playing, go to options and turn 'Sound' and 'Music' down to 0%)* BRIEF MINECART FIX: This is going to be brief, because I am busy right now. Instead of moving the whole Paulscode 1.3.2 folder to the 1.4 minecraft.jar, go inside the 1.3.2 Paulscode, and inside a folder called codecs (right now I don't have my PPC mac with me, so this is by memory) there should be a file called CodecJOrbis or something. Instead of replacing the whole 1.4 Paulscode, go inside both paulscodes and replace the CodecJOrbis only. I think that CodecJOrbis is at minecraft.jar\codecs\CodecJOrbis but it could be at minecraft.jar\sound\codecs\CodecJOrbis. This is by memory so it is not very detailed, but it should work.