A biometric audio security system includes providing an input voice audio source that is enhanced in two or more harmonic and dynamic ranges by re-synthesizing the audio into a full range PCM wave. A hardware key with a set of audio frequency spikes (identifiers) with varying amplitude and frequency values is summed with the enhanced voice audio input using' additive resynthesis. The voice and the spike set is compared against a users identification signature to verify user's identity. The set of audio spikes are user specific and are stored on the protected key device as a template, which would plug into the system. The template is determined by the owner/manufacturer of the system. The spikes are created and identified using the additive synthesis technique with a predetermined number of partials (harmonics). The identifiers include both positive and negative values with the amplitude and frequency values spaced in very fine intervals.
