Final answer:
The place theory best explains how we hear sounds above 4000Hz as it involves the activation of particular regions of the cochlea by different frequencies. The temporal theory contributes to pitch perception at lower frequencies up to about 4000Hz. Audiogram tests can graphically show hearing loss, which commonly includes a hearing dip at 4000Hz.
Step-by-step explanation:
The place theory best explains how we hear sounds above 4000Hz. According to place theory, different parts of the cochlea are activated by different frequencies. High-frequency sounds, such as those above 4000Hz, are detected because of where these sounds stimulate the basilar membrane inside the cochlea. At lower frequencies, however, both the temporal theory and place theory contribute to how we perceive sound. With the temporal theory proposing that the rate of action potentials correlates with the frequency of the sound, our perception of pitch can include a combination of both temporal and place cues up to about 4000Hz.
For frequencies above 4000Hz, however, the temporal theory is less applicable because there's a limit to how fast the hair cells can fire those potentials. The audiogram tests in clinical settings also help assess the hearing ability across a range of frequencies, typically from 250 to 8000Hz, and construct a profile of hearing loss which commonly shows a dip at the 4000Hz range, especially as a result of aging or noise damage, a condition known as presbycusis.