When you’re recording voice over you want to use my “Goldilocks” theory of recording: Not to Hot or the sound will clip and distort. And not too Cold or your voice will compete with the noise floor of the recording. And you want to err on the conservative side of a lower recording. So you often end up with a recording with a lower volume than the optimum.
Many talents try to fix this by “Normalizing” the final recording. But if there are volume “spikes” in your waveform, normalizing can have little effect–or actually turn down the volume of your recording. This video shows how to do it properly by adding an effect called a “Limiter”.