Yes, it is quite common for people to hear their own voice in their head, and sometimes it may sound different from how they perceive their voice when speaking aloud. When we speak, we not only hear the sound of our voice externally but also internally through bone conduction. This internal perception of our voice is often different from how it sounds to others due to the way sound travels through our bodies.
When we hear our voice externally (through the air) and compare it to the internal perception (through bone conduction), there can be a noticeable difference. The internal perception tends to have more low-frequency components and lacks some of the high-frequency nuances that others hear. This can lead to the feeling that our recorded voice or the voice we hear in our head doesn't sound like our "normal" voice.
Additionally, the way we perceive our voice is influenced by our auditory system and personal experiences. When we hear our voice externally, it combines with the vibrations we feel in our body, the resonance in our skull, and the overall auditory perception. In our mind, we may have an expectation of how our voice should sound, based on our own self-perception and previous experiences of hearing ourselves.
It's important to note that the perception of our voice can vary from person to person, and it can take some time to become accustomed to hearing recordings or experiencing our voice in different contexts.