The present invention relates to method, and apparatus relating to cellular radio communication. The patch may include an insulator for protecting the target from exterior, ambient IR and may include bar codes or other indicia uniquely associated with either the patch or the mammal. An active noise reduction filter is connected between the microphone output path and the loudspeaker input path, and the active noise reduction filter comprises at least one shelving filter. A touchdown signal is generated in response to the microactuator and the filtered voltage, wherein the touchdown signal indicates when the head contacts the disk.