A condenser microphone has an output circuit comprising an emitter-follower circuit; an impedance converter comprising an FET and at least one transistor of the emitter-follower circuit provided next to the FET; and the transistor having an emitter terminal provided with a constant-voltage circuit. The process includes the steps of: providing a sol including a volatile non-aqueous liquid and nanoparticles suspended in the non-aqueous liquid; processing the sol to form a plurality of droplets; depositing the plurality of droplets on a surface; and evaporating the non-aqueous liquid from the surface leaving a residue of nanoparticles. An optimal power parameter is calculated using the combinations not included in the combination tables based on results of the recording tests, to thereby quickly determine optimal parameter values. An object and methods of tracking objects are also disclosed. According to one aspect of the invention, the initial threshold is set to a score threshold that approximates an expected ratio of acceptable documents calibrated with respect to a set of reference documents. The vehicle-based communication module includes a transmitter for transmitting a challenge signal to the portable communication device when in a polling state to determine a presence of the portable communication device for allowing access to the vehicle.