Editing Digital audio (section)

===Telephony===
{{Main|Digital telephony}}

The rapid development and wide adoption of PCM [[digital telephony]] was enabled by [[metal–oxide–semiconductor]] (MOS) [[switched capacitor]] (SC) circuit technology, developed in the early 1970s.<ref name="Allstot">{{cite book |last1=Allstot |first1=David J. |chapter=Switched Capacitor Filters |editor-last1=Maloberti |editor-first1=Franco |editor-last2=Davies |editor-first2=Anthony C. |title=A Short History of Circuits and Systems: From Green, Mobile, Pervasive Networking to Big Data Computing |date=2016 |publisher=[[IEEE Circuits and Systems Society]] |isbn=9788793609860 |pages=105–110 |chapter-url=https://ieee-cas.org/sites/default/files/a_short_history_of_circuits_and_systems-_ebook-_web.pdf |access-date=2019-11-29 |archive-date=2021-09-30 |archive-url=https://web.archive.org/web/20210930151716/https://ieee-cas.org/sites/default/files/a_short_history_of_circuits_and_systems-_ebook-_web.pdf |url-status=dead }}</ref> This led to the development of PCM codec-filter chips in the late 1970s.<ref name="Allstot"/><ref name="Gibson26">{{cite book |last1=Floyd |first1=Michael D. |last2=Hillman |first2=Garth D. |chapter=Pulse-Code Modulation Codec-Filters |title=The Communications Handbook |edition=2nd |date=8 October 2018 |orig-year=1st pub. 2000 |pages=26-1, 26-2, 26-3 |publisher=[[CRC Press]] |isbn=9781420041163 |chapter-url=https://books.google.com/books?id=Tokk5bZxB0MC&pg=SA26-PA1}}</ref> The [[silicon-gate]] [[CMOS]] (complementary MOS) PCM codec-filter chip, developed by [[David A. Hodges]] and W.C. Black in 1980,<ref name="Allstot"/> has since been the industry standard for digital telephony.<ref name="Allstot"/><ref name="Gibson26"/> By the 1990s, [[telecommunication network]]s such as the [[public switched telephone network]] (PSTN) had been largely [[digitized]] with [[VLSI]] (very [[large-scale integration]]) CMOS PCM codec-filters, widely used in [[electronic switching system]]s for [[telephone exchanges]], user-end [[modems]] and a range of [[digital transmission]] applications such as the [[integrated services digital network]] (ISDN), [[cordless telephones]] and [[cell phones]].<ref name="Gibson26"/>