The story
Äänekoski is named after the nearby rapids. Folk etymology connects the name to the word ääni "sound", but Terho Itkonen has suggested another origin: a Sámi term meaning "big, large" (compare Northern Sámi eanas, "most").
Swedish sources mention a salmon fishery by the rapids around 1455, Ænækoski laxefiskeri. At the time, it was not a proper settlement and was located in the hunting grounds of the people of Sysmä. The Rautalampi parish was established in 1561, at the time it was a large parish covering most of Central Finland north of the Päijänne. The Laukaa parish, including the area of Äänekoski, was separated from Rautalampi in 1628.
A settlement named Äänekoski has existed at least since 1752. It remained a part of Laukaa until the parish was established in 1907 and the municipality Äänekosken maalaiskunta was established in 1911. At the time, Äänekosken maalaiskunta was called simply Äänekoski. The municipality was divided in 1932: the actual settlement of Äänekoski became the kauppala of Äänekoski, Suolahti became another kauppala while the old Äänekoski municipality was renamed Äänekosken maalaiskunta and its administrative seat was moved to the village of Honkola. Äänekoski and Äänekosken maalaiskunta still shared a parish.
The first industrial enterprises appeared in 1896–1900.
Four municipalities have been consolidated with Äänekoski: Äänekosken maalaiskunta in 1969, Konginkangas in 1993 and Sumiainen and Suolahti in 2007. Äänekoski adopted the coat of arms of Suolahti in 2007.
From Wikipedia’s article on Äänekoski, shared under CC BY-SA 4.0.5