Easily make loudness more uniform in Premiere Pro
This is a copy and paste from a similar previous question which I answered:

In order to even out the audio of a single stream; you will want to either mix by hand as noted above; or you can use dynamics; specifically Compression. 

Within the PPro audio mixer, apply dynamics to the audio tracks, or master track. 

You can then use the compressor within the dynamics filter, which you can use on all your tracks, to get your dynamic range all in line.

The simplest way to learn this is just trial and error; but looking at your waveform; you will want to:

Adjust the gain up- it's a pot/knob center column bottom. Use a ratio of about 2:1 to 6:1.

Last, click the checkbox on the bottom right of the dynamics filter for each track to enable the limiter. The limiter; a good setting is -2 db.

Then you want to adjust your threshhold in terms of attack and release, what you want to see on your audio (do your setup/testing on the loud sections and soft sections to find the sweet spot); is your compressor VU meter should just barely be jumping... when say someone is speaking. If it's spiking to high; gain down. If it's not jumping at all; gain up. 

This will balance out your audio so the soft sounds are adjusted up and can be heard, and the loud sections are not adjusted up; resulting in overmodulation. Its a much better way to smooth out your audio, decrease the dynamic range, and end up with audio that sounds far more balance.

Once you learn how to effectively use the dynamics filter on tracks, I think you will find you will be far more effecient in mixing your audio on the fly. It really does a decent job to just get everything in balance. Then; after you've done that, you can do back and sweeten the audio with a full mix; using a control surface or the pots, recording the pot movements via Touch Setting.