OTA TV commercial volume

[Kelly A]

Didn't pre-emphasis and de-emphasis precede stereo FM or TV audio broadcasting?

One of the points regarding FM broadcast audio processing was the concern regarding pre-emphasis, from a modulation limit context?

But again, wouldn't audio processing for digital transmission not be affected with these concerns? That was my point earlier.

You can't compare digital transmission with analog when it comes to DTV. As I mentioned, pre-de emphasis was for high-frequency noise reduction of analog FM, mono or stereo. Same with analog TV, just a different curve. Digital modulation doesn't require high-frequency noise reduction traditionally because the audio is a duplicate of the source, not a demodulated version.
Any audio processing (compression, limiting, dynamic EQ) for DTV is just for level control or enhancement at the source. As I've mentioned, there's no need or advantage for pre or de-emphasis.

I didn't read the full document, but one might look at the fact that apparently, there are still viewer concerns regarding the differences in audio levels between program content and commercials' content. Voluntary compliance might not be effective.

Unlike analog FM, the Commission isn't concerned with exceeding occupied bandwidth due to over-modulation with DTV carriers. The digital carrier is constant and unaffected by transient audio levels because the audio data packets are embedded with the other streaming data packets. The only result of excessive audio levels to, or from the decoded data stream, would be distortion from just over-driving A/D converters or other audio components. The Calm Act was created because the Commission was tired of complaints about viewers' perception that some commercials were too loud. There was no other way for the Commission to regulate or enforce what amounts to volume level because even in the analog days, one VU meter could be several decibels different in calibration to another VU meter. Instead, analog Frequency Modulation levels are regulated by their occupied bandwidth within the channel.
Again, I suggest taking a few minutes and reading more in the document links I sent. They do a good job of explaining what the Calm Act is, and how the ATSC arrived at the standards.

 

[RadioFan2J3]

You can't compare digital transmission with analog when it comes to DTV.

I agree, but remember, the earlier post:

They almost certainly do have the same sort of Orban audio processor you might use on radio (not exactly the same model because of some subtleties in how TV audio is modulated).

I took that sentence to be related to the TV audio of the older analog systems. So, I would have understood that to mean that some of the processing concerns which apply to over the air AM or over the air FM doesn't always apply to digital audio, especially and even DTV. Perhaps, it might be more correct to state that over the air analog audio has more challenges than the audio within a DTV package.

As I mentioned, pre-de emphasis was for high-frequency noise reduction of analog FM, mono or stereo. Same with analog TV, just a different curve. Digital modulation doesn't require high-frequency noise reduction traditionally because the audio is a duplicate of the source, not a demodulated version.
Any audio processing (compression, limiting, dynamic EQ) for DTV is just for level control or enhancement at the source. As I've mentioned, there's no need or advantage for pre or de-emphasis.

I understand the reasoning behind pre-emphasis and de-emphasis.

To a lesser extent, minor pre-emphasis has been used in some shortwave systems, as well, but that is an entirely different discussion.

Unlike analog FM, the Commission isn't concerned with exceeding occupied bandwidth due to over-modulation with DTV carriers. The digital carrier is constant and unaffected by transient audio levels because the audio data packets are embedded with the other streaming data packets. The only result of excessive audio levels to, or from the decoded data stream, would be distortion from just over-driving A/D converters or other audio components. The Calm Act was created because the Commission was tired of complaints about viewers' perception that some commercials were too loud. There was no other way for the Commission to regulate or enforce what amounts to volume level because even in the analog days, one VU meter could be several decibels different in calibration to another VU meter. Instead, analog Frequency Modulation levels are regulated by their occupied bandwidth within the channel.
Again, I suggest taking a few minutes and reading more in the document links I sent. They do a good job of explaining what the Calm Act is, and how the ATSC arrived at the standards.

And is there any enforcement ability with the ATSC developed standards? I think that might be the bottom line. As a standard, it might work well. Unless there is some mechanism to enforce those standards, it would appear that the problem with large differences in audio levels between program content and commercial content results in exactly the same problem as the earlier poster has discussed.

 

[Dr. Bob]

Forks gets almost twice the rain per year as Mobile, 120 inches vs. 67. It really comes down to how one defines "city." Forks is legally a city as far as WA State defines it, but I suspect Mobile passes some threshold in population that puts it on the top of the list. Astoria OR gets over 70 inches a year but only has 11,000 residents. Aberdeen WA gets 84 inches a year but only has a population around 15,000. I am guessing the folks who call Mobile the wettest city likely mean the "wettest city over 50,000 people."

Hilo HI gets 120 inches a year and has 47,000 people. 47,000 very wet people.

I researched this and a portion of the total for Forks appears to be snowfall. I agree that it is very wet there and, likely, Ku band satellite transmission would be highly attenuated assuming the rainfall rate is also high, which is the more important parameter for the Ku band. I have experienced the rain in Hilo. Beautiful place; very wet.

 

[Kelly A]

I agree, but remember, the earlier post:

They almost certainly do have the same sort of Orban audio processor you might use on radio (not exactly the same model because of some subtleties in how TV audio is modulated).

I took that sentence to be related to the TV audio of the older analog systems. So, I would have understood that to mean that some of the processing concerns which apply to over the air AM or over the air FM doesn't always apply to digital audio, especially and even DTV. Perhaps, it might be more correct to state that over the air analog audio has more challenges than the audio within a DTV package.

Correct statement. With analog modulation, audio processing (compression, limiting, clipping, EQ) first job is to keep the modulated carrier inside the assigned spectral real estate. Pre-emphasis is not a requirement, but a standard because receivers had de-emphasis built in. Eventually, multiband compression and manipulation of the audio were developed to enhance the audio (apparent loudness) by reducing the natural dynamic range (audio peaks). Digital audio used with DTV has none of those restrictions because peaks and dynamic range of the audio do not affect digital modulation or decoding. The audio packets are direct copies of the original audio source that are decoded at DTV by the receiver. Audio levels are maintained either in the recording process or can use audio processing, depending on the preference of the broadcaster. As I mentioned; NBC is one of the networks that choose not to use audio processing for DTV due to the inherent distortion and potential fatigue caused by such devices. I wholeheartedly agree with their thinking. Why intentionally distort the audio when it serves no purpose?

I understand the reasoning behind pre-emphasis and de-emphasis.

To a lesser extent, minor pre-emphasis has been used in some shortwave systems, as well, but that is an entirely different discussion.

Shortwave is deader than dead, so any discussion would amount to a history discussion.

And is there any enforcement ability with the ATSC developed standards? I think that might be the bottom line. As a standard, it might work well. Unless there is some mechanism to enforce those standards, it would appear that the problem with large differences in audio levels between program content and commercial content results in exactly the same problem as the earlier poster has discussed.

If enough complaints were received at the Commission, generally enforcement involves contacting the station(s) and asking them to fix the issue and then report back. I suppose someone could get in trouble for frequent and willful violations of the Calm Act, but I've not heard of any serious fines ever being issued.

 

[Dr. Bob]

Correct statement. With analog modulation, audio processing (compression, limiting, clipping, EQ) first job is to keep the modulated carrier inside the assigned spectral real estate. Pre-emphasis is not a requirement, but a standard because receivers had de-emphasis built in. Eventually, multiband compression and manipulation of the audio were developed to enhance the audio (apparent loudness) by reducing the natural dynamic range (audio peaks). Digital audio used with DTV has none of those restrictions because peaks and dynamic range of the audio do not affect digital modulation or decoding. The audio packets are direct copies of the original audio source that are decoded at DTV by the receiver. Audio levels are maintained either in the recording process or can use audio processing, depending on the preference of the broadcaster. As I mentioned; NBC is one of the networks that choose not to use audio processing for DTV due to the inherent distortion and potential fatigue caused by such devices. I wholeheartedly agree with their thinking. Why intentionally distort the audio when it serves no purpose?

Shortwave is deader than dead, so any discussion would amount to a history discussion.

If enough complaints were received at the Commission, generally enforcement involves contacting the station(s) and asking them to fix the issue and then report back. I suppose someone could get in trouble for frequent and willful violations of the Calm Act, but I've not heard of any serious fines ever being issued.

Here is a link to a paper by Robert Orban from 2010 where he discusses the limitations of the metering used to measure loudness for ATSC television:

https://www.thebdr.net/wp-content/uploads/PDF/Audio/Processing/using-the-itu-bs-1770-and-cbs-loudness-meters-to-measure-loudness-controller-performance.pdf

A couple of the pertinent sentences in the conclusions are: ”Several studies have shown that the loudness “comfort range” for typical television listening is +2 dB, -5 dB. Beyond this range, a viewer is likely to become annoyed, eventually reaching for the remote control to change the volume (or worse from a broadcaster‘s point of view, to mute the commercial).”

The study referenced is: ATSC A/85:2009 Annex E, “Loudness Ranges”

If this study is accurate, somehow it’s in the best interest of the broadcaster (including NBC) to keep all program loudness within the referenced ranges either by automatic means, like audio processing, or manual means, like someone with their hand on a potentiometer somewhere in the chain prior to broadcast.

 

[bigdonho]

Here is a link to a paper by Robert Orban from 2010 where he discusses the limitations of the metering used to measure loudness for ATSC television:

https://www.thebdr.net/wp-content/uploads/PDF/Audio/Processing/using-the-itu-bs-1770-and-cbs-loudness-meters-to-measure-loudness-controller-performance.pdf

A couple of the pertinent sentences in the conclusions are: ”Several studies have shown that the loudness “comfort range” for typical television listening is +2 dB, -5 dB. Beyond this range, a viewer is likely to become annoyed, eventually reaching for the remote control to change the volume (or worse from a broadcaster‘s point of view, to mute the commercial).”

The study referenced is: ATSC A/85:2009 Annex E, “Loudness Ranges”

If this study is accurate, somehow it’s in the best interest of the broadcaster (including NBC) to keep all program loudness within the referenced ranges either by automatic means, like audio processing, or manual means, like someone with their hand on a potentiometer somewhere in the chain prior to broadcast.

CBS made a loudness controller that that took into account peak levels and frequency ranges. It was used by a number of TV stations to overcome the loudness variations in different sources. Does anyone make anything similar?

 

[Dr. Bob]

CBS made a loudness controller that that took into account peak levels and frequency ranges. It was used by a number of TV stations to overcome the loudness variations in different sources. Does anyone make anything similar?

Orban has a free software meter that includes both the CBS loudness meter and two examples of the ITU standard BS.1770:

METER — Orban

www.orban.com

And all audio processors designed specifically for television include some sort of loudness controller to conform to the BS.1770 standard which is not to say someone, somewhere, is using a processor without a BS.1770 compliant loudness controller.

 

[Kelly A]

If this study is accurate, somehow it’s in the best interest of the broadcaster (including NBC) to keep all program loudness within the referenced ranges either by automatic means, like audio processing, or manual means, like someone with their hand on a potentiometer somewhere in the chain prior to broadcast.

But if the content is monitored and adjusted for loudness as it's being ingested into the playback server or cloud service, isn't that the same thing? As I said in my explanation of digital over analog audio, digital is nothing more than an exact copy of the original source being played back as it was recorded/ingested.
With all respect to Bob Orban, Frank Foti, or whoever in the audio-processing business, assuming there is a workflow for adjusting proper levels at the input, there simply is no longer a need to adjust levels, let alone introduce distortion via a traditional audio processor.

 

[RadioFan2J3]

But if the content is monitored and adjusted for loudness as it's being ingested into the playback server or cloud service, isn't that the same thing? As I said in my explanation of digital over analog audio, digital is nothing more than an exact copy of the original source being played back as it was recorded/ingested.

But very conditional. If the content audio level is adjusted at the input level, then the output levels will be far more constant and fewer listener complaints.

If the content from the various sources is not consistent in audio levels, then that becomes part of the final OTA product, and those level differences are annoying to the viewer/listener.

I believe that was the original concern, that the OTA audio has significant level differences at the ears of the viewer/listener and whatever the broadcaster is using in the audio chain is not keeping the levels within the range as pointed out in the post from Dr. Bob.

With all respect to Bob Orban, Frank Foti, or whoever in the audio-processing business, assuming there is a workflow for adjusting proper levels at the input, there simply is no longer a need to adjust levels, let alone introduce distortion via a traditional audio processor.

Whatever additional distortion is introduced by the digital equivalent audio level control devices is probably more acceptable to the non-purist listener than the constant manipulation of the volume for the OTA signal as viewed in the average home.

But since the listener is apparently having concerns with audio levels, that workflow process is failing.

Wasn't that kind of the point of the original poster?

 

[Kelly A]

But very conditional. If the content is adjusted at the input level, then the output levels will be far more constant and fewer listener complaints.

But if the content from the various sources is not consistent in audio levels, then that becomes part of the final OTA product, and those level differences are annoying to the viewer/listener.

I believe that was the original concern, that the OTA audio has significant level differences at the ears of the viewer/listener and whatever the broadcaster is using in the audio chain is not keeping the levels within the range as pointed out in the post from Dr. Bob.

But that amounts to enforcing a workflow and proper procedures during ingest more than throwing some box that alters the natural dynamics of the original content for the sake of being easy. Checking audio levels on the way in is simple. Buying an expensive box which excuses someone for not doing their job is not a good solution.

Whatever additional distortion is introduced by the digital equivalent audio level control devices is probably more acceptable to the non-purist listener than the constant manipulation of the volume for the OTA signal as viewed in the average home

Reducing dynamic range and adding distortion is a subtle and subliminal annoyance when watching long form programming. Audio processing negatively effects everything. TV is different than radio, in that a viewer watches/listens for an average of thirty to ninety minutes where a radio listener listens less intently for fifteen minutes or less.

But since the listener is apparently having concerns with audio levels, that workflow process is failing.

That's an over-generalized statement. Not all viewers experience level concerns, nor on ALL stations or networks. In fact, one could easily argue that percentage is very tiny.

Wasn't that kind of the point of the original poster?

Again, this is one station and one instance. Why would someone make sweeping compromises in audio quality because of an occasional incident, in this example, on one independent station in the Atlanta DMA?
Talk about throwing the baby out with the bathwater...

 

[Dr. Bob]

But if the content is monitored and adjusted for loudness as it's being ingested into the playback server or cloud service, isn't that the same thing? As I said in my explanation of digital over analog audio, digital is nothing more than an exact copy of the original source being played back as it was recorded/ingested.
With all respect to Bob Orban, Frank Foti, or whoever in the audio-processing business, assuming there is a workflow for adjusting proper levels at the input, there simply is no longer a need to adjust levels, let alone introduce distortion via a traditional audio processor.

In theory, it is the same no matter where it happens in the process but the devil is in the details. As far as having an exact copy, there are many major motion pictures that have high dynamic range audio; fine if you are in a theater. If you believe the ATSC A/85 standard, most television viewers don‘t desire high dynamic range audio for television viewing. In that case, someone or something needs to correct the dynamic range of the audio. This could be someone at a mixing console “riding gain” or an automatic device and it could be done prior to ingestion. Your view seems to be neither one is desirable and is distortion? When the product was produced, someone used an audio mixer (at the very least) to control the levels. In the case of motion pictures, someone was doing that in post.

I’m in the camp of having an audio processor before the transmitter in the event something didn’t meet the standard. I would hope +99% of the time it would do nothing but those few percentage or tenths of a percent, it would correct the error. This is completely different than (almost) any concept of radio broadcast processing.

 

[W1DAN-]

Howdy folks!

I work in TV (started in radio in 1976). The CALM act was implemented to force ATSC A/85 compliance because commercial advertising firms demanded that their commercials be louder than other programming and thus created audio tracks that did not match the Dolby metadata value. Pretty quickly folks used fixed metadata values and hopefully set their audio levels to match.

At the beginning of DTV I once measured the network audio "dialog levels" from one of the big three TV networks as received at our TV station and found that the average commercial audio level was about 10dB hotter than network programming. And our promotions department felt it was good to run audio levels peaking at 0dBFS. Our broadcast audio processor took 5 seconds to recover from their promo audio.

The CALM act is adhered to in two ways:
1. A human or automation device scans the audio levels of a program or commercial clip and adjusts the gain of the entire clip to match the proper level (usually -24dB LKFS using the ITU BS.1770 measurement standards).
2. Similar to what radio stations do, an audio processor is placed downstream to automatically adjust whatever audio master control feeds it. Often these are set for "stun" where all audio is smushed.

I have experienced both methods, and obviously the first choice is the best from an artistic view and the one that we use at the station I work at now. I also have come across commercials that seem to increase the perceived sonic level by performing some form of phase modification that while measures OK, sounds louder to the ear. Then there is improper level adjustment after downmixing 5.1 audio to stereo.

As a broadcaster, we have to demonstrate that we are adhering to the CALM act. This can be done by a logger or real-time meter. I would bet that the TV station the original poster is complaining about is not adhering to the CALM act. Using the Orban Loudness Meter connected to your TV is a great way to learn about TV audio levels of your local OTA TV stations.

Dan

References:

A/85, Techniques for Establishing and Maintaining Audio Loudness for Digital Television - ATSC : NextGen TV

This Recommended Practice provides guidance to broadcasters and creators of audio for high-definition (HD) or standard-definition (SD) television content. It recommends production, distribution, and transmission practices needed to provide the highest quality audio soundtracks to the digital...

www.atsc.org

https://www.telestream.net/pdfs/whitepapers/wp-calm-act-compliance.pdf

Historical:

https://aes2.org/wp-content/uploads/2021/09/Loudness-Management-Chapter-5.14-r03-a-1.pdf

 

[Kelly A]

This could be someone at a mixing console “riding gain” or an automatic device and it could be done prior to ingestion. Your view seems to be neither one is desirable and is distortion?

That isn't what I said. Here in the 2020's there is no mixing console or faders involved. Audio levels are adjusted at the ingest point to server or cloud provider prior to the file being moved-in. That level adjustment as required typically uses a digital software audio editing tool. In some locations, they use an application like Telestream Vantage to automatically check conformance of the audio/video file, including audio level limits, then it automatically adjusts and ingests the file to it's final destination. My view is exactly what I said prior; that installing an expensive device in each station to adjust levels like the old days by reducing dynamics and adding distortion is needlessly old school and degrades the audio as compared with the original source.

When the product was produced, someone used an audio mixer (at the very least) to control the levels. In the case of motion pictures, someone was doing that in post.

In 2024, commecials are sent to the station or network MC hub as files and ingested into the streaming playout servers or cloud service prior to airing.

 

[Kelly A]

I have experienced both methods, and obviously the first choice is the best from an artistic view and the one that we use at the station I work at now. I also have come across commercials that seem to increase the perceived sonic level by performing some form of phase modification that while measures OK, sounds louder to the ear. Then there is improper level adjustment after downmixing 5.1 audio to stereo.

That's a great point and one that gets missed. Audio in some spots are intentionally equalized or enhanced to stand out over other spots or programming. If you looked at the audio via a peak reading meter or LKFS, the level would be perfectly in line. The station can only be responsible to ingest and play the spot. Also the broadcaster or network can't be held responsible when someone sets their Samsung TV audio settings to some sort of synthesized surround setting which pops into the mode when additional L-R levels are present in a spot. That's why when the original complaint in this thread came about, the first thing I asked was if there were any audio settings in their TV that were non-standard stereo.

 

[W1DAN-]

Hi Kelly and all:

Yes, often a spot that is traditionally equalized to enhance the midrange and then compressed heavily will be jarringly louder than an un-processed talk show or soap opera; and it is almost impossible to smooth this transition using level adjustment or processing. My mention of phase modification of the audio at the production house seems to be a new method over the last few years, and I wonder if the technique is something like aggressively compressing L-R? Either way, the production house is doing their best to skirt the intention of the CALM act.

You mention Telestream Vantage. We use that for video transcoding and I created a few workflows that correct audio levels, but there is also Minnetonka's file-based correction which I have not used. The editors at our TV station author audio at the correct BS.1770-3 level as verified by programs that are installed on their edit workstations such as Izotope Insight. We used to use Dolby LM100's, but they only measured to BS.1770-2, and is not upgradable to BS.1770-3 or -4.

An interesting check at home would be to connect your TV's audio (SPDIF or analog headphone jack if available, and of course make sure your TV audio settings have no processing added) to a PC with the Orban Loudness Meter and see what various stations in your market are doing over time. Just remember that the BS.1770 measurement is a long-term measurement that is much longer than a traditional VU meter, and peaks are not much of a concern here as they were for analog BTSC TV audio or today's analog FM.

Cheers,
Dan

 

[Dr. Bob]

Hi Kelly and all:

Yes, often a spot that is traditionally equalized to enhance the midrange and then compressed heavily will be jarringly louder than an un-processed talk show or soap opera; and it is almost impossible to smooth this transition using level adjustment or processing. My mention of phase modification of the audio at the production house seems to be a new method over the last few years, and I wonder if the technique is something like aggressively compressing L-R? Either way, the production house is doing their best to skirt the intention of the CALM act.

You mention Telestream Vantage. We use that for video transcoding and I created a few workflows that correct audio levels, but there is also Minnetonka's file-based correction which I have not used. The editors at our TV station author audio at the correct BS.1770-3 level as verified by programs that are installed on their edit workstations such as Izotope Insight. We used to use Dolby LM100's, but they only measured to BS.1770-2, and is not upgradable to BS.1770-3 or -4.

An interesting check at home would be to connect your TV's audio (SPDIF or analog headphone jack if available, and of course make sure your TV audio settings have no processing added) to a PC with the Orban Loudness Meter and see what various stations in your market are doing over time. Just remember that the BS.1770 measurement is a long-term measurement that is much longer than a traditional VU meter, and peaks are not much of a concern here as they were for analog BTSC TV audio or today's analog FM.

Cheers,
Dan

Question. Does your station have live programming, like local news? If so, what or who insures that the audio levels on those programs comply with -24 dB LKFS standard?

 

[secondchoice]

I wonder if the production houses realize a significant percentage of the population mutes their loud commercials?

 

[Kelly A]

I wonder if the production houses realize a significant percentage of the population mutes their loud commercials?

Chances are they have data that would indicate their work breaks through more than being muted. Otherwise, they wouldn't keep doing it.

 

[W1DAN-]

Dr. Bob:

Yes we have live stereo shows as well as recorded ones. In both cases the audio engineer mixes to within a window of +/-2dB of -24dB LKFS referencing an internal loudness meter that is set to ATSC A/85 in the console. There is a limiter in the mix bus, but it is not run hard, just a few dB of G/R on peaks. The stereo line output goes to master control (or via a record server for editing and playback), then encoding/multiplexing and through the transmitter with no level or dynamics changes.

When I was at the commercial TV station years ago, same mix process, but they hit the console mix bus limiter harder, and in the master control program line we had an Orban 6200, then later a Linear Acoustic Aeromax processor set carefully and artistically to bring the wide range of audio (about 30dB variance) from network, our control room and hot commercials to within an average of about 5dB using slow release time constants and limiting on compressor overshoots. It was comfortable listening at the home where one did not need to grab the volume control, but still had some feeling of dynamic range. In the analog days we had the Orban 8182A/8185 processor/encoder in master control with the usual FM channel pre-emphasis limitations.

Dan

 

[Kelly A]

Dr. Bob:

Yes we have live stereo shows as well as recorded ones. In both cases the audio engineer mixes to within a window of +/-2dB of -24dB LKFS referencing an internal loudness meter that is set to ATSC A/85 in the console. There is a limiter in the mix bus, but it is not run hard, just a few dB of G/R on peaks. The stereo line output goes to master control (or via a record server for editing and playback), then encoding/multiplexing and through the transmitter with no level or dynamics changes.

But in your example, that's a newscast or local programming mics and audio, not spots/breaks, correct?
This discussion is about loud spots in breaks. Somehow I doubt you have an MC that runs spot playout audio through a mixer.