What options will I meet when a service or device offers 'dialogue boost' or 'enhance dialogue', and do they all work the same way?

Partially verified: the curator re-read S21, S22; S23, S24, S26 were not re-read by the curator and rest on the producer's pinned reading. 'Dialogue boost/enhance' labels cover different mechanisms: device-side processing (Apple tvOS Enhance and Enhance More, the latter stated to possibly alter the original mix), pre-made selectable audio tracks (Amazon Dialogue Boost levels; SVT Enhanced Speech) and encoder-side parametric dialogue metadata (Dolby AC-4, producer reading). Record the mechanism and source before comparing them. Curator qualifications: Partially verified: the curator re-read S21, S22; S23, S24, S26 were not re-read by the curator and rest on the producer's pinned reading. Curator GET 2026-10-23 of the sources not re-read (mechanical source evidence, not semantic verification): S23: HTTP 200, bytes equal to the producer pin; S24: HTTP 200, bytes equal to the producer pin; S26: HTTP 200, bytes differ from the producer pin. Pages read 2026-10-22; no playback or measurement. Dolby AC-4 white paper and BBC trial pages (S23, S26) from producer reading; Amazon gives no measurements. Limitations: Pages read 2026-10-22; no playback or measurement. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://support.apple.com/guide/tv/change-audio-settings-atvba773c3c9/tvos",
      "note": "Apple Support tvOS: change audio settings (bytes equal pin); Amazon: Prime Video debuts Dialogue Boost (live; differs from pin)"
    },
    {
      "url": "https://www.aboutamazon.com/news/entertainment/prime-video-dialogue-boost",
      "note": "Apple Support tvOS: change audio settings (bytes equal pin); Amazon: Prime Video debuts Dialogue Boost (live; differs from pin)"
    },
    {
      "url": "https://professional.dolby.com/siteassets/technologies/dolby_atmos_ac-4_whitepaper.pdf",
      "note": "Apple Support tvOS: change audio settings (bytes equal pin); Amazon: Prime Video debuts Dialogue Boost (live; differs from pin)"
    },
    {
      "url": "https://arxiv.org/pdf/2208.08960",
      "note": "Apple Support tvOS: change audio settings (bytes equal pin); Amazon: Prime Video debuts Dialogue Boost (live; differs from pin)"
    },
    {
      "url": "https://www.salford.ac.uk/school-of-science-engineering-and-environment/salford-improves-audio-on-bbc-casualty",
      "note": "Apple Support tvOS: change audio settings (bytes equal pin); Amazon: Prime Video debuts Dialogue Boost (live; differs from pin)"
    }
  ]
}