A threshold that is "near or at the limits of the audiometer" describes:

A corner audiogram specifically describes a type of hearing loss where the thresholds are located near or at the limits of the audiometer, usually indicating that the individual has some residual hearing at very low frequencies but significantly impaired hearing for mid and high frequencies. This type of audiogram often appears in cases of profound hearing loss, where the individual cannot hear sounds above a certain frequency range, thus showing a "corner" effect in the graph.

In contrast, a cookie bite audiogram typically shows a dip in the mid frequencies, suggesting a different audiological profile, while a flat audiogram indicates similar hearing levels across frequencies, without the limits issue. A Type A tympanogram pertains to middle ear function and does not address the issue of audiometric thresholds. Understanding the characteristics of different audiograms is crucial in determining the nature and degree of hearing loss, which is why recognizing a corner audiogram is important.