INHD has a setup similar to HDNet that has audio tones.
However, this is an exercise in futility. There are far too many places for audio levels to lose cal in the broadcast chain, starting with the networks themselves. Each one cals differently and sends the audio through a different chain, often compressing, sometimes compressing and expanding. Using digital inputs, if the left/center/right balance is correct using your receiver's tones, it should be right with the cable box as well.
If you are interested in proper volume calibration across different sources, the best you'll probably get from broadcast is by using digital inputs from both your DVD and cable box. Calibrate the audio using Avia then know that you are calibrated properly and any error in volume through the cable box is caused by the broadcaster and is beyond your control.