Abstract: Method and system for providing security to a space by detecting an unauthorized presence in the space using voice recognition. A plurality of acceptable voice patterns is generated from sounds of authorized users and stored in the security system. Sounds in the space to be protected are detected and a current voice pattern is generated from at least one sound detected in the space to be protected. The current voice pattern is compared with entries in the stored voice lists to determine a level of difference or a level of similarity between the current voice pattern and the content of the voice list. If the determined level constitutes a discrepancy according to predetermined criteria, an alarm response is initiated. Further, if the determined level constitutes a matching between the current voice pattern and an entry in an emergency list of voice codes that were entered by authorized users, a predetermined emergency action is performed.