Note: 16k is about as low as you can go on bitrate. 32 sounds much better (but is larger...)

ffmpeg -i rtsp://USER:PASS@xxx.xxx.xxx.xxx:554/videoSub -vn -c:a aac -af "dynaudnorm=b=0:m=50:g=5" -b:a 16k -hls_list_size 65535 -hls_time 2 -t 00:10:03 "/home/george/Documents/AudioMonitor/LivingRoom/$(date -d "today" +"%Y-%m-%d %H:%M:%S").aac" &


Implemented in shell script as:

#!/usr/bin/env bash

cd $(dirname $0)

pwd="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"

ffmpeg -i rtsp://USER:PASS@xxx.xxx.xxx.xxx:554/videoSub -vn -c:a aac -af "dynaudnorm=b=0:m=50:g=5" -b:a 16k -hls_list_size 65535 -hls_time 2 -t 00:10:05 "${pwd}/LivingRoom/$(date -d "today" +"%Y-%m-%d %H:%M:%S").aac" &