CACrown ArchivesHistory · sources · collections
EN/FR
Search
Menu
Research dossier · General Reference

Pulse-code modulation

Digital representation of sampled analog signals

Cross-disciplinary reference desk with index cards, atlas, dictionary and catalogue
General referenceInterpretive dossier study · Crown Archives visual atlas
Record originEnglish Wikipedia
Text licenseCC BY-SA 4.0
Source revisionSep 6, 2026
Entity authoritySource title only
Source-derived summary

Pulse-code modulation (PCM) is a method used to digitally represent analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM stream, the amplitude of the analog signal is sampled at uniform intervals, and each sample is quantized to the nearest value within a range of digital steps. Claude Shannon, Bernard Oliver, and John Pierce were inducted into the National Inventors Hall of Fame for their PCM patent granted in 1952.

Editorial summary

The public source identifies “Pulse-code modulation” as digital representation of sampled analog signals. This brief keeps that definition visible, then builds a research path around Pulse-code, modulation and Digital.

Editorial reviewA dependable orientation record for establishing vocabulary, names and a first evidence trail. The current lead gives the account dated anchors—1952—that can be checked directly. The selected authority fields contribute no independent date. Its value is orientation rather than verdict, with Pulse-code, modulation and Digital providing the first useful test.
Editorial analysis

Why this record matters

A short description can identify a subject without explaining its stakes. For “Pulse-code modulation”, the useful work is to connect “digital representation of sampled analog signals” to the records capable of establishing context and consequence.

Evidence profile

Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Sep 6, 2026. The first chronological checks are 1952.

Critical limits

Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.

How to read it

Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.

Best used for
  • Subject orientation
  • Search vocabulary
  • Locating named sources
Verify next

The closest primary source, responsible institution and strongest cited specialist reference.

Three-step research path

  1. Establish the record: confirm the title “Pulse-code modulation”, its source revision and the description used here.
  2. Expand the search: follow Pulse-code modulation primary sources, Pulse-code modulation archive and Pulse-code research across catalogues and specialist indexes.
  3. Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.

Questions for further research

  1. Which source most directly establishes the central claim about “Pulse-code modulation”?
  2. What terminology or title could unlock a more precise catalogue search?
  3. Which institution is responsible for the underlying evidence?
Subject index

Search terms from this dossier

Source & attribution

This entry incorporates text from “Pulse-code modulation” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.