There are two issues I want to address with the sound.
The first is that I find the voices sound weak to me. I think that may have been a result of the noise reduction I did. I tried a few things to process the sound to see if I could give the voices more body.
The other is the lack of environmental sound. There is no real background sound and there are several places where I think sound effects are needed. An example is when the prosecutor picks up some books and there is no sound. I left this until later.
I use Audacity for my audio work. I’m not sure how it compares to other audio programs, but the price (free) is right. It seems to have all the capabilities that I need.
My first test was to try out sound compression. Compression reduces the volume of the peaks while leaving the rest of the sound the same. I found this allows me to turn up the volume of the voices, which makes them sound stronger. I tried several different settings, but I couldn’t tell the difference, so I just used the default settings.
The compression did increase the background noise, which hadn’t been apparent before. The additional noise wasn’t acceptable, so I reran the noise reduction and brought it under control, without a noticeable change in the voice quality.
I’ve always though of reverb as something different from echo, but that didn’t seem to be the case. I tried some different settings, but didn’t learn much from that.
Then I found that the reverb effect had some presets for different types of rooms, such as big room, small room, bright room and dark room. I found that the big room and bright room settings made the voices sound weaker. That was the opposite of what I wanted. The small, dark room setting seemed to give more body to the voices.
To my ear, the combination of the effects I tested does bring me closer to the quality of sound I want. However, the effect isn’t as strong as I’d like it to be. I want to see if there is anything else I can try. My copy of Audacity has something like 140 effects, and my copy of Premiere Pro (CS4) has about 80 audio effects. Apparently you can get more if you want them. I’m familiar with maybe a half dozen or so, but I have no idea what most of the rest do.
I’ll need to do some more research. I could use some advice.