Last year, I proposed a simple "exchange rate" way to think about the differences between rodent and human hearing. A lot of people liked the audiograms from that plot, so I figured I would share a few more. So: here are the audiograms for four different mammals that might be of interest.
In practice, exact species vary, and transgenics with slightly different hearing might exist. These data may be taken as representative for rabbits, rats, mice, and small primates. The most-sensitive regime is highlighted for each animal as the dark part of the curve. The human audiogram (from an ISO standard) is overlaid in grey for comparison.
In general: it's no surprise that there is a general bias towards higher-frequency sensitivities in animals. That's why we often have to measure (and speak) in terms of ultrasound when it comes to animals. A general rule of thumb holds that for mammals, frequency is inversely-proportional to size.
I got these from Rickye Heffner's fantastic archive; be sure to check it out for more.