the dts clear dialogue technology poised to transform home entertainment

In conversation with Martin Walsh from DTS, Layla Laidouci explores Clear Dialogue – the company’s cutting-edge audio solution for vocal intelligibility.

As home entertainment grows more advanced, the maturing market is highlighting a widespread frustration. Unintelligible dialogue presents an obstacle to immersion, stripping movies and other creative material of artistic intent.

Clear Dialogue, the new audio post-processing solution by DTS, supports all languages and various content sources to solve this challenge. The specialist in immersive entertainment introduced its audio separation technology in September 2024 to critical acclaim in the consumer electronics world. Showcased at CES 2025, Clear Dialogue uses AI to differentiate audio between dialogue, music, and sound effects. We speak to Martin Walsh, vice president of DTS, about the research and mission behind the Clear Dialogue concept.

Problem solving

“Traditional digital signal processing solutions have their limitations,” Walsh begins. “We identified the root causes of the problem we wanted to address. These were primarily content mixing techniques, TV speaker quality and listening environments. We unmix and remix soundtracks to mitigate these factors.”

“While modern home entertainment audio production quality has become equivalent to movie production quality, the products reproducing it are not always the same.”

Walsh acknowledges that home entertainment has more audio channels and dynamic range than ever before, but product usability limits its performance. “While modern home entertainment audio production quality has become equivalent to movie production quality, the products reproducing it are not always the same,” he points out. “Most individuals are watching content on inexpensive, thin, often backfiring stereo speakers built into their flatscreen TVs. This means all the additional channels of high dynamic range audio are compressed down to low-powered TV speakers, compromising dialogue intelligibility in the process.

“Background music or sound effects can often overpower spoken words, especially in action scenes or ambient environments. Customisable audio settings for these purposes are essential but often deficient in many TV models. The environments in which people watch TV can also impact dialogue quality. For instance, viewers are likely to reduce the volume when listening at night.

“Another popular remedy for owners of multichannel audio systems is to increase the loudness of the centre channel relative to the other channels. Although this can be effective, it also creates a spatial imbalance for non-dialogue audio in the centre channel.”

Martin Walsh

The tech challenge

Signal processing techniques have been advanced to address these dialogue intelligibility issues. Walsh says the technologies apply gains to areas where human speech is likely to be present, but this can affect EQ (equalisation) within that frequency range.

“Object-based audio formats, such as DTS:X, allow content creators to encode dialogue as a separate audio object to independently process that dialogue object at the receiving end. However, such options can disrupt current content creation workflows and dialogue objects have not been widely adopted so far.”

Walsh is referring to the company’s proprietary audio codec, which delivers immersive sound where it would occur in space.

“Even if object-based dialogue processing is adopted, the technique cannot be applied to legacy, non-object-based content,” he continues. “Some content providers are creating special dialogue-forward versions of their soundtracks: for instance, Amazon introduced a feature called Dialogue Boost on Prime Video.

“This feature allows users to increase the volume of dialogue relative to background music and effects, making it easier to hear and understand spoken words in the supported content.

“One downside of this approach is that content producers cannot predict listener preferences or the environment in which the content is consumed. Instead, they must make an educated guess for each new version of the mix, often disrupting the original artistic intent or the original mix and misaligning with individual listener preferences.

“Recent advancements in machine learning fully isolate dialogue from the rest of an audio track and apply exclusive processing to it. DTS Clear Dialogue separates voices from the music and effects of a soundtrack before applying any dialogue-specific EQ.

“Clear Dialogue creates a bespoke dialogue mix for each user based on their preferences and can also include other information, such as the playback environment and limitations of the playback equipment.”

“There is evidence suggesting that separating dialogue from the soundtrack and enhancing it through gain or EQ can improve the listening experience for individuals with mild to severe hearing loss.”

Can Clear Dialogue tackle hearing loss?

DTS continues to conduct research into the effects of DTS Clear Dialogue on those with hearing difficulties. “This question is complex because hearing loss can vary from person to person,” says Walsh. “The current solution might not be ideal for individuals with significant hearing loss, as increasing TV speaker levels too much can cause substantial secondary distortion. It’s crucial to ensure the level of processing does not result in an uncomfortable listening experience for others present in the room.

“There is evidence suggesting that separating dialogue from the soundtrack and enhancing it through gain or EQ can improve the listening experience for individuals with mild to severe hearing loss.

“As hearing declines, distinguishing dialogue from background increases cognitive load on the listener and becomes more challenging. Boosting the dialogue-to-background ratio can make a significant difference without needing to adapt the solution to each listener’s specific hearing profile.”

Immersion and dialogue

Clear Dialogue amplifies vocals without distorting the whole audio mix, introducing clarity even in scenes with loud background noise or complex soundscapes. “When dialogue is intelligible, narrative flow is maintained and keeps viewers engaged,” says Walsh. “This is vital in television shows and movies to ensure the audience can comprehend the story, characters, and emotions being conveyed.

“Reading subtitles can significantly diminish the immersion in the story, as focus must shift to reading the text rather than observing the rest of the screen. Test feedback has been encouraging, highlighting how simple adjustments to the levels of dialogue, music, and effects can result in a much less stressful entertainment experience. Many said they were unaware of the cognitive effort this required.

“When dialogue is intelligible, narrative flow is maintained and keeps viewers engaged.”

“This solution is focused specifically for televisions, leveraging the machine learning hardware capabilities present in contemporary TV sets. The next generation of our DTS Clear Dialogue technology will encompass set-top boxes, soundbars and AV receivers. In certain cases, these solutions may incorporate more advanced signal processing features tailored to the specific hardware.”

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