For example, of the two words lion and lioness, lion is unmarked for gender (it can denote either a male or female) whereas lioness is marked, since it denotes only females. b. Explicitly characterized by or having a particular linguistic feature.
20 Hertz to 20,000 Hertz is the frequency response range that a human can hear. So in answer to your question 20 Hertz would be the lowest pitch a human can hear.
However, this results in extremely high frequencies, far higher than those that any known species can perceive (some bats can hear frequencies as high as about 250,000 Hz). Rodents can generally hear higher frequencies than humans. It's difficult to give an average frequency for the hearing ability of rats, but it would be much higher than for people. The hearing range for rats is about 200-75,000 Hz. Beyond that, I can't really answer your question, as I'm not really sure what you are requesting; hopefully this helps somewhat!