The Larsen Effect

Before I talk about “feedback” in a people management context, as a one-time musician and performer, the word has a second definition for me.

If you’ve been to a live music performance or two, the chances are you’ve experienced the distinctive , ear-splitting, nerve-jangling, wince-inducing howl of audio feedback through a large PA system. It’s truly a horrible experience and sets most people’s teeth on edge in the same way that scraping fingernails down a blackboard does.

The first principles of audio feedback were discovered by Danish scientist Søren Absalon Larsen, hence the blog title. I’m no expert on the physics behind it but basically it occurs when when a microphone (or instrument) picks up its own sound and amplifies it again. You can read more about it here if you want to hear from someone who is an expert on the physics of it…

The good news is that these days you can build into your sound system rig specific “feedback killers” (like this one, pictured below) which are designed to identify the frequencies that are causing feedback in your performance and “kill” them, stopping the feedback before it even happens without having too big an impact on the overall sound quality. Very handy, I’m sure you’d agree.

The thing is though, not all feedback is bad. Certainly not if you’re an electric guitar player, usually of quite a rock music-y persuasion. Using an electric guitar and a suitable amp, it is possible to control feedback and actually make it harmonic rather than horrific. There have been some true masters of the craft but for my money, none have topped the genius of Jimi Hendrix who took his ability to make the guitar feedback in a controlled way and built it into a key part of his performances that set him apart from his (many) contemporaries who are now also regarded as guitar geniuses. One of the most famous examples of him using this technique during a live performance is in the video below where he performs “The Star Spangled Banner” at Woodstock, firstly causing his guitar to feedback then controlling the pitch of it expertly with its tremolo arm.

As with so many of these things, I watch this video in awe from 2015 but can you imagine the impact of him doing it in the 1960s when no-one had ever really seen anything like that before?!

So what have we learned about feedback in a musical performance setting?

• It occurs in a particular environment with the right conditions
• It can be awful, toe-curling and impossible to listen to
• You can build in processes and systems that kill feedback before it even starts
• However, when executed by a master of the craft, it can really enhance performance and be a truly memorable experience

Now, I was going to link this to people management somehow, wasn’t I?

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This post was inspired by and written as part of the #FeedbackCarnival curated by Helen Amery.