Can't hear sound. (Minecraft Mod Coder Pack beta 1.7.3)

I’m trying to use Mod Coder Pack for Minecraft version beta 1.7.3, but I can’t hear sound at all.
This is such an old version, that I couldn’t find any solutions anywhere, but hoping somebody here can help.

Here is a screenshot of the errors I’m getting: https://imgur.com/KcMx7Dj it just does that for every sound in the game.

java.io.IOException: Server returned HTTP response code: 403 for URL: http://s3.amazonaws.com/MinecraftResources/sound3/dig/sand1.ogg at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source) at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source) at java.net.URL.openStream(Unknown Source) at net.minecraft.src.ThreadDownloadResources.downloadResource(ThreadDownloadResources.java:142) at net.minecraft.src.ThreadDownloadResources.downloadAndInstallResource(ThreadDownloadResources.java:124) at net.minecraft.src.ThreadDownloadResources.run(ThreadDownloadResources.java:58)

(Same as what is shown in the image.)