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The buttons on Zenith’s original “clicker” remote were a mechanical marvel
(www.theverge.com)
This is a most excellent place for technology news and articles.
The article does indicate that animals were sensitive to the noises:
"It did have its flaws: people found that jingling keys or coins could be picked up by the TV’s microphones and accidentally change the channel, and the high-pitch frequencies from the remote were discernible by pets."