Adele’s Grammy Cautionary Tale: How in-Ear Monitors Can Help (or Hurt) an Artist

Tiny though they may be, in-ear monitors can certainly have a huge impact on a live performance, delivering a custom audio feed directly into an artist’s head. As integral as an amp or microphone, in-ear monitors also isolate noise and protect hearing. Not least of the benefits, the monitors are a handy excuse when things don’t go well. “My ears weren’t working!” has been an artist’s rejoinder for everything from cueing the wrong playback to singing off-key.

But sometimes things really do go wrong. In the case of Adele stopping and restarting her performance of George Michael’s “Fastlove” during her Grammy tribute to the late singer Sunday, she had issues with a high-frequency sound in her in-ear monitor during rehearsals, Grammy producer Ken Ehrlich tells Billboard. As for what happened during the show, however, the Grammy producer “can only speculate” that it was an in-ear issue, though the matter is being investigated, according to a Grammy rep.

Tour manager Harry Sandler, who has worked with Katy Perry and John Mellencamp, tells Billboard that frequency issues can often be an issue during a live show. “There are so many frequencies in a building, they can overlap and create problems, whether with a guitar and a wireless monitor or an in-ear that goes to a belt pack.”

Interference from a neighboring channel is not uncommon. Working a busy stage, monitor engineers can easily find themselves negotiating among 40 different audio frequencies, allocated among the band, backup singers and dancers, as well as key engineers and sometimes security personnel. Separate channels that are used for things like police and TV crew communications can also interfere.

“You work to make the wireless ‘clean,’ which has to do with antenna placement and assigning the principal performers the most robust frequencies — things that usually get worked out during rehearsal,” says monitor engineer Kevin Glendinning, who got his start in radio frequencies with The Rolling Stones in 2000 and is about to go on tour with John Mayer.

As the staging setups and communications demands have gotten more complicated, the in-ear technology has also improved since being introduced sometime around 1995 by Jerry Harvey, a monitor engineer working for Van Halen who has since launched his own firm, which dominates the category. An estimated…