Ask a Lawyer and Get Answers to Your Legal Questions
Thank you for using the forum. My name is ***** ***** I hope to assist you with this matter.
If the neighbor is a fellow tenant (so you both rent from the same landlord), the matter is dealt with by complaining to the landlord (in writing). If the landlord refuses to deal with the issue, or if the issue continues, you can sue the landlord in small claims court (see: http://www.courts.ca.gov/selfhelp-smallclaims.htm) for breach of contract - specifically "breach of the implied right of quiet enjoyment"
The court can award you both an injunctive order (a court order requiring that the landlord take enforcement action against the neighbor up to or including an eviction), and monetary damages to compensate you for the reduced value of the unit during the period of the noise disturbance.
Short of filing a lawsuit, you can try to mediate the dispute with them - contact your local bar association and request referrals to mediators, a third party neutral can often help you reach a mutually agreeable resolution. Use the bar association's referrals to contact a mediator or two, the mediator will then contact the other party to set up a mediation session, and you can go from there - hopefully resulting in a formal or written settlement agreement, and save yourself the time and expense of litigation.