Q Why is the sound on a Blu-ray disc not uniform? I am playing them through my Samsung Blu-ray player and an HD Panasonic TV. I don't have a sound system, just the speakers built into the TV. I have found that while the picture is excellent, the volume of sound level varies greatly. Some parts are very loud, while others can hardly be heard.

To hear them properly I have to constantly hold and adjust the volume control. As the same thing is happening on several of the discs, I am wondering if I need to adjust something in order to get a uniform sound level.

-- R.B.

A This is a constant source of questions to my column. The usual complaint is about commercials being louder than the television programming, which is a function of the average volume at which the material is recorded. The loudest possible volume is the same for a TV program or a commercial, but the average volume of the commercial is much higher.

In the case of Blu-ray, you are dealing with dynamic range. Dynamic range is the possible volume range, from the lowest audible sound to as loud as it can get. Blu-ray has extremely wide dynamic range and the programs are recorded to take advantage of it, just as in a movie theater. People don't complain about dialogue being unintelligible in the movie theater. That's because the theater has set the volume for you. Likewise, people rarely complain that the special effects are too loud. That's because you expect it. Think of the last time you saw an action movie in the theater. You heard the dialogue very clearly, but when there were explosions, they were LOUD. When you play a Blu-ray at home and turn the volume up so you can clearly hear the dialogue, the special effects may blow you out of your chair, just like at the theater. Most people are not used to that at home (or their system can't reproduce it without lots of distortion) and it has them reaching for the volume control.

People ask about a uniform sound level as if it is something they want. If the sound level was truly uniform, everything would come across as if in a monotone. Some variation in volume is desirable, and natural. Life does not come across at a single volume level! What you want is something with less range, so soft sounds are a bit louder and louder sounds are not as loud.

Look in the player's audio setup menu for something called "Dynamic Range Control" and turn it on. This will bring the sounds more in proportion with each other. Your TV may also have a setting for dynamic range control, which will help those of you annoyed with loud commercials. Legislation called CALM (Commercial Advertisement Loudness Mitigation) was passed by the FCC about loud commercials. You can read more about it at http://www.fcc.gov/encyclopedia/loud-commercials where a complaint process is detailed. Though the legislation went into effect on Dec. 13, 2012, it seems we are still being blasted by loud commercials. Between this and the HD channel fiasco going on with cable companies and basic cable encryption, it seems like some people at the FCC may be asleep at the switch!

Contact Don Lindich at www.soundadviceblog.com and use the "submit question" link on that site.