“Definition
An auditor may attend lectures and other class meetings, to take part in class discussions, and receive written confirmation of attendance. An auditor will not receive evaluations of participation, and will not be allowed to submit assignments or write examinations and tests, except by special and express permission. The University's Code of Student Conduct will apply to auditors.”

https://web.archive.org/web/20080314174319/http://www.utoron...


Gasthörer {m}
- observer
- (guest) auditor.
- guest student
http://www.dict.cc/deutsch-englisch/Gasthörer.html


“auditor –
someone who goes regularly to class for a college course without asking for or receiving credit for taking the course”
http://www.macmillandictionary.com/dictionary/american/audit...


“German term or phrase: Gasthörer
[confidence] 4 +4 ______auditor
[confidence] 3 ________Guest students”
http://www.proz.com/kudoz/german_to_english/education_pedago...