What the Ear Hears (And Doesn’t): Inside the Extraordinary Everyday World of Frequency

Musician Mainwaring takes a deep dive into the “extraordinary world of vibration, waves, and frequency” in his zippy debut. As he writes, “from communicating where the next meal is to drumming out a courtship dance... living things rely on hertz.” His tour through the auditory world sees him explain that until the 20th century, an A note could be “anything from Handel’s 422 Hz to Beethoven’s 455 Hz” depending on the country; that understanding frequencies enabled the development of Polaroid cameras and printers; and that the frequency of a honeybee’s wings whirring is 250 Hz, which makes the note of B. He routinely ties frequencies to various pieces of popular music: Brahms’s “Lullaby” helps “illustrate the pitches” of WWII air-raid sirens, for example, and the bonds that join the atoms in nitrous oxide vibrate at a frequency the same as Andy Williams’s opening note of “Moon River.” Though he can get a bit into the weeds (“A frequency of 5,000 Hz... will have a peak hair cell sensitivity around ten millimeters along the cochlea”), Mainwaring’s well-tuned sense of humor and ample use of puns help the jargon go down. Music-minded readers won’t regret tuning in. (Dec.)