The human footstep is one of several signatures that can serve as a useful parameter for human detection. In early research, the force of footsteps was measured on load cells and the input energy from multiple footsteps was detected in the frequency range of 1-4 Hz. Cress investigated the seismic velocity response of outdoor ground sites to individuals that were crawling, walking, and running. In his work, the seismic velocity response was shown to be site-specific and the characteristic frequency range was 20-90 Hz. The current paper will present vibration and sound pressure responses of human footsteps in a broad frequency range. The vibration and sound in the low-frequency band are well known in the literature and generated by the force component normal to the ground/floor. This force is a function of person's weight and a manner of motion (e.g. walking, running, etc). Forces tangential to the ground/floor from a footstep and the ground reaction generate the high frequency responses. The interactions of foot and the ground/floor produce sliding contacts and the result is a friction signal. The parameters of this friction signal, such as frequency band and vibration and sound magnitudes as functions of human walking styles, were studied. The results of tests are presented and discussed.