Simply download a trial version of the Adobe Software. The Adobe Download Assistant will download automatically when you begin downloading the trial software.
For more information about downloading Adobe trial software please see our discussion on "How do I download a trial version of Adobe's Creative software?" or the document "Adobe Download Assistant FAQ."
You are correct Bill_Lindsay not all of our trials are currently using the Adobe Download Assistant. Some of our software also utilizes the Akamai Download Manager and others have direct download options. The majority of our trial software is utilizing the Adobe Download Assistant however.
As for Audition from your description it does sound like it is still utilizing the Adobe Download Assistant. Part of using the Adobe Download Assistant is the need to initially install the software.