"Great distortions annoy; lesser distortions fatigue." Great quote from one of our readers and it's quite appropriate as we start looking at Listener Fatigue. I didn't want to just examine the nature of fatigue, however, I wanted to steer the discussion into something I actually know about: design. How does design influence listener fatigue and what can designers do to lessen it and why?
But first, let's get our definitions in order. If you walk into a ENT's office and ask "what is listener fatigue?" you'd probably get a standard answer such as " listening to something too loud for too long". This is legitimate and something all of us should avoid as our ears can be permanently damaged by too-much-too-loud. I am always saddened when we are on the hiking trail and we say something to a fellow hiker with ear buds on - and that hiker can't hear a thing we're saying - his only clue is to see our lips moving in his direction. That's too loud. When I listen to music on my iPod I can hear everything around me as well and that's a fairly good indication you're not stressing your hearing out.
The listener fatigue I am referring to is unrelated to the volume level. Rather, it is the fatigue caused by an imbalance in a stereo system - and there are many aspects of a system's balance that can cause these audible distortions: too bright, too tizzy, too confused, too little dynamics, too much emphasis on the upper harmonic structure, etc.
Music is a form of communication between people - an amazing form that can transmit emotions without words and without reference.
A musical beat gets a listener's toe tapping in synch regardless of their reference point, language or cultural biases. When two tones together produce a pleasing harmony (actually a third tone is produced) we understand the intent of the composer, as well when two tones produce a discordant note (a sharp or flat third tone) that grates on us - we also get the intent of the composer - to unsettle us. And when a composer uses several off-tones in a row and then gives us a pleasing combination of tones and harmonies - we call this a resolve - where conflicting tones resolve into a successful tone.
This grouping of frequencies we call music mirrors our own successes, failures, fights, releases, harmonies. Just think about struggling to open a jar - you make a discordant grating "grrrrrrrr" sound until the jar opens (the resolve) and you give a satisfying "aaaahh" - and the note you use to exclaim "aaah" is an even whole note, while the "grrrr" is an odd sharp or flat of the whole note (like the white keys of a piano vs. the black keys).
No doubt some more musically savvy people than I will jump down my throat about the analogy I use, but I think you get the point of what I am trying to say. There are pleasing sounds and unpleasant sounds and hearing too many unpleasant sounds can cause listener fatigue of the type I am talking about.
Tomorrow let's start with how I learned to adjust circuitry to reduce listener fatigue.