When you speak out loud, your brain is actively engaged in producing the speech. The process of speaking involves motor planning and execution, where your brain sends signals to the muscles involved in producing the sounds, controlling the airflow, and shaping your vocal tract. This entire process requires a significant amount of neural resources.
One of the ways our brain efficiently manages these tasks is by temporarily suppressing the auditory feedback loop that allows us to hear our own voices while speaking. This phenomenon is known as "vocal motor control" or "auditory-motor gating." When you speak, your brain anticipates the sound you will produce based on the motor commands it sends to your vocal apparatus. It uses the internal prediction of your voice's sound to guide further articulation and adjust ongoing speech.
If the auditory feedback loop wasn't temporarily suppressed, the real-time sound of your voice would reach your ears while you're speaking, creating a confusing and distracting situation. The brain prioritizes the motor control aspects of speech production, allowing us to concentrate on the act of speaking and adjust our speech output based on internal predictions rather than real-time auditory feedback.
However, if you listen to a recording of your own voice played back to you, it may sound unfamiliar and different from how you perceive your voice internally. This is because you are now hearing your voice from an external perspective without the filtering effect of bone conduction, which makes your voice sound deeper and richer when you hear it while speaking.
In summary, the brain employs vocal motor control to optimize speech production by suppressing the auditory feedback loop temporarily, allowing us to focus on speaking without being distracted by the sound of our own voice.