Final answer:
The old version of Tonopen tonometry results were acquired through an analog display, while the new version uses a digital display with auditory signals for results.
Step-by-step explanation:
The subject of this question is Tonopen tonometry, a medical procedure used in optometry and ophthalmology to measure intraocular pressure (IOP), which is crucial for evaluating patients for the risk of glaucoma. In the old version of tonopen tonometry, the results were typically acquired through an analog display, wherein the pressure readings were indicated on a scale or dial. In contrast, the new version of tonopen tonometry often employs a digital display that provides the IOP readings on a small screen, which can be more accurate and easier to read compared to the older analog methods. Moreover, the new versions of tonometers may provide an auditory signal or beep to indicate successful measurement completion.
Considering the provided multiple-choice options and the evolution from analog to digital displays in devices, the correct answer appears to be option 'a' - Digital display; auditory signal for the new version, and by elimination, this implies an Analog display for the old version, even though no specific mention is made about the old version's signal.