Anything Goes : Digital Audio in Television and Movies? by Irving Stanton-VGC

Having recently dived in and bought an HD flat screen 1080p television, I have really noticed a huge difference in sound quality between stations/shows. The digital audio signal received in some cases can be outstanding, and in others it's a tad bit to be desired. I had allot of experience with analog audio mixing live theatre shows, recording actor voice overs, and live music. However, I am somewhat confident dealing with digital audio right now on a mid level status, but there is still allot that I need to learn. My question is this, isn't there a standard to follow when it involves digital audio for sound recorders/engineers? As well as the final mix of a television program? What has happened to all that great audio we once heard before digital audio came along in movie and television broadcasting? Just off the top of my head if I answer my own question, it comes down to budget I believe, but if you're picked up by a national broadcaster shouldn't there be a top notch standard to follow in order to be signed to any deals? Now, even with low budgets, common sense tells me that there is always away to get a good mix to protect the integrity of the overall production and to protect oneself as an excellent audio engineer that is doing a sound design for a show. Has anyone else noticed these issues with digital audio in television and movies or are my ears getting too old to hear properly, hence making a not so distant future appointment to see an audiologist?