[Galaxy S 4 Active Q&A, Help & Troubleshooting] thisisapoorusernamechoice:
I'm glad I can help you, xda is all about learning and I like to pay it forward. I completely understand your concern with the sound issue, that actually scared me away from installing any roms on my active, I'm still on my stock rom. Unfortunately I can't really tell you much about the few available roms for this device.

I really miss the look and feel of cyanogenmod (loosely referred to as AOSP or stock android), not to mention the performance improvements. That's why I read up and learned how to de-odex the stock ROM, which gives you the ability to then decompile and modify system apps. Somewhat intimidating stuff at first, but I am (maybe was) a total n00b and I'm starting to get the hang of it. If you really want to learn how to hack and mod your phone while stuck on stock rom, this thread will get you started, a majority of the code is the same.

For a couple of easier modifications, replacing the stock touchwiz launcher with another default launcher like NOVA launcher gives you much more control of the look and feel of the homescreens, icons, etc. and I like to use it to disable/tone down screen transition animations, freeing up some system resources. You can use titanium backup to uninstall preloaded system apps that you neither use nor want, again freeing up space on your phone. This is called de-bloating, here's a list of apps safe to remove:

-AllShare ControlShare Service

-AllShare FileShare Service

-Amazon

-Amazon App Suite

-Amazon Kindle

-Amazon mp3

-Android Live Wallpapers

-Ant Radio Service

-Ant+ Plugins

-Audible

-Backup Assistant Plus

-Black Hole

-BlurbCheckout

-Briefing

-Bubbles

-Calculator

-Calendar

-Caller Name ID

-Circles

-Cloud

-Cloud print

-com.samsung.android.sdk.spenv10

-com.sec.android.app.FlashBarService

-com.sec.android.sviewcover

-com.sec.msc.nts.android.proxy

-DigitalPenSDK

-DioDictService

-DirectConnectManager

-Email

-Enterprise Sim Pin Service

-Enterprise SysScope Service

-Enterprise VPN Services

-EnterprisePermissions

-EpsonPrintService

-Face Unlock

-Google Now Launcher

-Google Play Books

-Google Play Games

-Google Play Movies & TV

-Google Play Newstand

-Google Search

-Google+

-GroupPplay

-Hangouts

-HealthService

-Help

-Homescreen Tips

-HP Print Service Plugin

-IMDB

-InteractiveKeyboardTutorial

-KNOX

-KNOX notification manager

-KNOX store

-KLMS Agent

-Live Wallpaper Picker

-Magic Smoke Wallpapers

-Manage accessibility

-Maps

-mc3

-Memo

-Messaging

-Mobile Print

-mobileprintsvs_cups

-mobileprintsvs_cups_backend

-Movie Studio

-Music Visualization Wallpapers

-My Verizon Mobile

-Nearby Service

-NFC Service

-NFC Test

-NFL Mobile

-Phase Beam

-Photo Screensavers

-PickupTutorial

-Polaris Office 5

-Print Spooler

-Quick Office

-RealRacing2

-S Memo

-S Note Provider

-S Translator

-S Voice

-Samsung Account

-Samsung Billing

-Samsung Books

-Samsung Calendar SyncAdapter

-Samsung Content Agent

-Samsung Games

-Samsung Knox

-Samsung Memory SyncAdapter

-Samsung Print Service

-Samsung Print Service Plugin

-Samsung Push Service

-Samsung Updates

-Samsung WatchOn

-Security Policy Updates

-Setup 4.4.2-10

-Setup Wizard 4.4.2

-Setup Wizard 1.0

-Setup Wizard 1.3

-ShareShotService

-Slacker Radio

-SmartActions

-SmartActions Android Framework

-SmartActions Proprietary Framework

-SyncMLSvc

-Talkback

-Translate

-Travel Wallpaper

-Trip Advisor

-Try air move

-Virtual Tour Viewer

-VMware Ready

-Weather

-WFDS Print Service Plugin

-Yahoo! Finance

-Youtube

-Zappos

Sorry if the debloat list has Verizon stuff in it, I obviously got it at Verizon S4 thread. You should be perfectly fine removing any AT&T apps, I certainly did haha.

Now that you've got SafeStrap, do yourself a favor and flash this mod. Just download the Galaxy_Mod_Ultimate.zip and install it in SafeStrap recovery. You should see marked battery life improvement within a day.