create a folder on your computer with all the sound files you want to upload.
then open a terminal and type in the following:
rsync -v -e ssh /Users/yourUserName/FolderName/*.* firstname.lastname@example.org:/root/Bela/projects/ProjectName/
where FolderName is the folder containing your audiofiles (i assumed you put the folder in your home directory which would be called after your username.
similarly in the second part of the command you have to substitute the name of your project for ProjectName.