Replacing space between sentences

Hello, all. I started using Audacity maybe 4 months ago to record and edit audiobooks. I think I understand the basics, but certainly have a lot to learn. I’m looking for a better way to handle gaps (containing breaths, sniffs, keytaps, etc) between sentences of the book. Here’s my process:

  1. Record an empty, quiet room for a few seconds followed by some speech. Perform noise reduction on that.
  2. Select about a quarter second of the quiet part of (1) copy it.
  3. In the audiobook, highlight the parts between sentences and paste the quiet sample enough to create about the same gap between sentences.
  4. Repeat for the whole book.

There must be a better way. This takes an incredibly long time. Just being able to select a between-sentence part and then basically say, “fill this with however much of that nice quiet part is needed to keep the selected area the same length”. Or any number of other ways.

Is there a better way? Like I said, I’m very new at this. I’m working my way through the effects, one by one, but there are a lot to learn about. Thank you in advance.

Take a look at this.

Five words, perfect answer. Thank you.