recording sound at different times

I am running windows 8.

here’s the Situation. I have a voice recording that I did a few days ago. I now have to record some additional information to insert into that recording. When I did the recording and inserted it you could tell they rerecorded at different times because of the volume differentiation and the overall sound of it.

I did do the Additional recording on a different computer but using the same microphone.

my question is: how do like Combine both recordings together and then make them sound the same?

When I listen to the new recording and it gets to the part where a inserted the new sound you can tell there is a difference and then a few seconds later he goes back to the original recording.

Does this make sense?

Yes your question makes sense, but unfortunately it is hard to fix. Human hearing is incredibly sensitive and can pick up tiny clues to distance and environment in voices. If a recording is made in a kitchen, it is likely to sound like it was made in a kitchen, whereas if it is made in a living room it will sound quite different. The distance from the microphone will also make a noticeable difference to the timbre of the voice. Even a mood change can make a noticeable difference to the sound.

The Equalization effect can sometimes help in that it can be used to adjust the bass, brightness and other frequency characteristics of the sound.

If you could post a couple of short samples from the two takes, we may be able to make specific suggestions. See here for how to post samples to the forum: https://forum.audacityteam.org/t/how-to-post-an-audio-sample/29851/1