We occasionally receive a complaint accusing us of purposely blasting the audio on commercials and other programs. I have never understand why any station or advertiser would want to manipulate audio levels just to make consumers mad, but that has been a perception for a long time by some people. Certainly, the human ear can detect differences in audio modes, and Digital TV programs come in a wide variety of sound. Most shows are in stereo or surround sound and some are still in mono, so you definitely can hear a difference between modes, but there should not be a huge difference in audio levels.
When I say difference, I mean grabbing the remote control to turn the volume up or down in a quick panic to protect your hearing. That’s not normal and means something is wrong. Fortunately, not everyone has that severe a problem, but it does happen and I could never understand how it happened. I mean, I know what’s going on, but I had not been able to duplicate it until this weekend. The solution requires a little detective work in the audio menus, but can be resolved relatively easily.
If your TV is connected to an antenna, it automatically detects which audio mode is being sent and routes it to the correct speakers, usually the left and right built-in to the set. There is however an audio menu that allows you to select a different mode manually. This can be changed accidentally, but if you just have a basic setup with no external equipment, check the audio menu to be sure it is set for stereo. Do not use any Surround or Dolby Digital mode!
If you have a cable or satellite box connected to the TV with an HDMI cable, it’s a bit trickier to trace because there’s an audio menu on the box and the TV. Normally, they “talk” to each other and set the mode automatically. These boxes often receive software updates that can change to modes and cause issues. Each box is different and may take some detective work to find the audio menu. I suggest looking at the TV menu first and again, make sure it is set for stereo and not surround or Dolby Digital, then search how to get to the cable or satellite box menu if the TV is correct.
Let me show you first what is happening:
Here’s your basic stereo program, like Local News, Judge Judy and other syndicated shows. The audio comes on channels 1 & 2 as stereo sound and the TV reproduces it on its’ built-in stereo speakers. The TV “expects” only two audio channels and sends it to the speakers. These are full volume audio channels containing music and dialog.
A Surround Sound, or Dolby Digital program sends up to 8 channels of audio. Each channel has a different function and the levels are dependent on the audio in each channel. Channels 1 & 2 only contain effects, like music and ambient audio. Channel 3 carries the dialog or actor’s voices. It is usually the center channel in the system.Channel 4 is for the sub-woofer. Very low bass sounds, explosions and rumbles are carried here. Channels 5 & 6 are the rear speakers and carry audio effects which allow a jet sound fly through your living room. Channels 7 & 8 displayed here are for SAP, or the second audio program. This can either be Spanish commentary or Descriptive Audio where the action on screen is described for the visually impaired.
Stereo programs may also contain SAP audio on channels 7 & 8.
Although everyone has different brands, models and sound setups, let’s just assume you are listening to the built-in speakers on the TV. If it is expecting Dolby Digital or surround sound, it will always reproduce channels 1 & 2 as being full left and right sound. Notice in the pictures above, a real surround sound show will only have music and effects on channels 1 & 2 and maybe a little dialog if you crank the volume up. Then a stereo commercial comes on and the volume blasts you out of your chair. That’s a sure sign the two devices are not talking and the wrong mode is being sent to the speakers.
Like I said, the audio mode is “supposed” to be set automatically between a cable box and the TV. Some people like to feed the Dolby Digital audio from the TV to the surround receiver, which is why you can set it manually. Most people take the digital audio straight from the cable box to the surround sound system which means it is sending the same audio to the TV, which may not be correct for a stereo only TV. Most set top boxes also have regular red / white RCA style audio connections for the TV. It all depends on how your system is setup on which cables to use. It’s easier using the HDMI cable, but as you can see, it can cause issues when the box and TV do not communicate properly.