You can hear your own pulse, for example. From this, normally, our hearing is able to "tune". But it happens.
Due to an unsuccessful filling in the tooth, you can "receive" the radio channel. The rarest punishment, but it happened.
To remove the vibrations of the skull, to amplify and record the sound is not so difficult, in principle.
The ear perceives air vibrations in the external environment. If a person hears something that a good microphone cannot record (corresponding to the hearing range and sensitivity of a person's hearing), then this may mean that the person has glitches or some kind of hearing impairment, or both. Also, for example, any buzzing, squeaking, etc. can be heard from increased pressure.
To clarify, if there are no sound vibrations in the air, then these are some glitches or illness. Because a sound wave in your ear should come from a sound source, which means that it can be caught by a microphone on the way (unless the microphone is worse in sensitivity than your ear or stupidly perceives some frequencies).