The memory apparatus incorporates a drum, mounted for rotation, and a series of hard mounted heads, spaced from the drum magnetic recording medium surface. The mounting structure includes spaced parallel aligning bars, utilized to precisely align the magnetic heads prior to finally fixing them to the structure, and resilient plastic wedges utilized to maintain a bias against the aligning bars, to compensate for the stresses induced in the assembly process. The precise spacing from the magnetic medium is accomplished by placing a spacing film over the drum, which film is removed after final assembly, leaving the proper head-tomedium gap. The final configuration is maintained by the use of epoxy adhesive to secure the heads to the aligning bars and retaining bars. The frame structure and head utilize the same metal alloy to maintain the head-to-medium gap during temperature variations. The resulting apparatus may be utilized in a voice response system for producing computer ordered, human voice response, to various commands. In this application the drum is rotated at a rate of one revolution per second and the head gap, head-to-medium spacing, and medium thickness, controlled to produce a relatively flat response characteristics over the frequencies of importance and thereby enable the use of relatively simple amplifiers with linear response characteristics.