Legal Question in Real Estate Law in California

Withholding rent puts you at risk for eviction. You need to make a "paper trail" of complaints to the landlord, using the magic words "breach of the implied covenant of quiet enjoyment" that is implied by law to be a term of every lease. Also document the other tenant's violations, with dates, times and if possible recordings. Once you have a body of evidence to prove your case, send one last written complaint stating how many times you have complained and that they have done nothing. Give them 72 hours to take action against the other tenant or you will sue. If they still do nothing there are plenty of attorneys who would be interested in your case at that point.

The "implied covenant of quiet enjoyment" has little or nothing to do with noise, including noise generated by a neighbor. The term "quiet enjoyment" has to do with freedom from conflicting claims to a right to possession of the property, such as, for example, claims from a previous tenant or from someone claiming a right as a new owner. I agree with much of what Mr. McCormick recommends, but your rights are doubtful if premised solely on the implied covenant of quiet enjoyment.