Humans cannot reliably report auditory attributes on absolute internal scales.

Evidence

The absolute or difference thresholds can only be used to measure psychophysical functions that relate attributes of sound events to simple functions having only two values. Often, a psychophysical function which represents an auditory percept with a continuous scale is desired, for example the mapping of sound pressure levels between 0 dB and 120 dB to the perceived loudness of an auditory event. There are many methods to estimate such psychophysical functions. … The task is, naturally, very complicated, as the subjects cannot access the absolute measure of the auditory attribute. For example, the subject’s ability to report, say, the loudness of a sound on an absolute scale or in relation to a sound heard more than a few seconds earlier is limited. As will be shown later, some clever systems have been found to define complex psychophysical functions, such as the relation of the SPL and loudness, or the sound spectrum and the loudness spectral density. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 895