The scene is familiar: you’re so caught up in your crime novel that you completely overhear the 12th ring of your telephone. The crossword puzzle got you so hooked that your bus stops 5 stations after your supposed destination. Similarly, typing that message on your mobile phone while crossing the street almost gets you killed because you don’t hear the approaching traffic. There are times when we unintentionally block out certain sounds and other outside goings-on that would otherwise distract us from what we’re currently doing. This type of “hearing loss” is called selective hearing and has been the focus of much research as of recently.
Hearing Loss, Tones, and Colors
Recent research done by Dr. Nilli Lavie at University College London, showed that being engrossed in a difficult task makes us blind and deaf to other sources of information. Dr. Lavie ran two groups of test subjects through an exercise. One group was asked to identify changing colors on a pictures (= simple), whereas the other group was asked to answer not only questions about colors, but also about shapes on the picture (= requires more concentration). What the test subjects did not expect was that during the exercise a tone was played to them. The results were astounding: 80% of those who were given the easy exercise claimed to have heard the tone, in sharp contrast with the 20% of those who were given the difficult test.
Hearing Loss: Limited brain bandwidth for hearing?
So far the most commonly accepted hypothesis for this “artificial hearing loss” is that our visual and hearing senses are trying to share the brain’s limited processing capacity (or bandwidth). Lavie’s findings may contribute to disproving the long-held notion that hearing has no real dependence on attention. Though hearing is often employed as one of the body’s natural defenses, alerting us of dangers we may not have been able to see coming, Lavie’s experiment shows that it can be temporarily paralyzed through deep, focused visual concentration.
In fact, similar – and better researched – phenomena occur when processing visual information. The famous invisible gorilla test, where test subjects engulfed in a basketball game failed to observe a man in gorilla suit stalking around the playfield. This is just to highlight that processing sounds is highly dependent on the brain – and not only on our ears being intact. Thus, for hearing loss due to “too much attention” there’s only that much that a hearing aid (let alone an Audicus hearing aid) can do.