A system for performing an authentication to enable a user to access a site monitoring system via a user interface, the authentication capable of voice authentication by a voice command and non-voice authentication, the voice authentication having at least one threshold, the at least one threshold being dynamically adjustable between false-rejection and false-acceptance and the at least one threshold including a degree of match between a voice signal and a voice pattern, the system comprising a user device, the user device having: a memory configured to store the at least one threshold; and a processor in communication with the memory, the processor configured to: adjust the at least one threshold for the voice authentication, the adjustment to the at least one threshold being based on at least the geo-location data for the user device and the time since the last non-voice based login with the site monitoring system by the user of the user device associated with the site monitoring system, the at least one threshold being adjusted to increase a probability of false-rejection when the user device is not proximate a site monitored by the site monitoring system, and the at least one threshold being adjusted to increase a probability of false-acceptance when the user device is proximate the site monitored by the site monitoring system and when a time since the last non-voice based login with the site monitoring system by the user of the user device is within a predefined time period; and perform the voice authentication based on the adjusted at least one threshold to authenticate the user to determine whether to enable the user to access a predetermined functionality for the site monitoring system based on the performed voice authentication. a memory configured to store the at least one threshold; and a processor in communication with the memory, the processor configured to: adjust the at least one threshold for the voice authentication, the adjustment to the at least one threshold being based on at least the geo-location data for the user device and the time since the last non-voice based login with the site monitoring system by the user of the user device associated with the site monitoring system, the at least one threshold being adjusted to increase a probability of false-rejection when the user device is not proximate a site monitored by the site monitoring system, and the at least one threshold being adjusted to increase a probability of false-acceptance when the user device is proximate the site monitored by the site monitoring system and when a time since the last non-voice based login with the site monitoring system by the user of the user device is within a predefined time period; and perform the voice authentication based on the adjusted at least one threshold to authenticate the user to determine whether to enable the user to access a predetermined functionality for the site monitoring system based on the performed voice authentication. adjust the at least one threshold for the voice authentication, the adjustment to the at least one threshold being based on at least the geo-location data for the user device and the time since the last non-voice based login with the site monitoring system by the user of the user device associated with the site monitoring system, the at least one threshold being adjusted to increase a probability of false-rejection when the user device is not proximate a site monitored by the site monitoring system, and the at least one threshold being adjusted to increase a probability of false-acceptance when the user device is proximate the site monitored by the site monitoring system and when a time since the last non-voice based login with the site monitoring system by the user of the user device is within a predefined time period; and perform the voice authentication based on the adjusted at least one threshold to authenticate the user to determine whether to enable the user to access a predetermined functionality for the site monitoring system based on the performed voice authentication.