i totally do not mean to worry you or anything, but long-term use of cannabis has been associated with schizophrenic-like symptoms in some individuals. it is rare, however, the reason i brought it up is because auditory hallucinations are one of the top symptoms of early schizophrenia, or at least schizo type symptoms.

usually though, if a drug is going to activate some dormant trait towards a disorder like that, it would begin to develop in the first few weeks or months of using. so assuming you have been toking longer than a few months, you are fine. just thought i would share though, as i was grateful to be informed of this by an abnormal psych professor.
thanks for helping out my log!
peace