As with all tools, to get maximum performance from your ears, you need to know how they work, treat them well and use them with care. Professor David McAlpine, director of the UCL Ear Institute has written a five-point plan to set you on the way for better listening and hearing!
Pay attention! One easy way to improve your listening is to put some effort into it. Trying to listen to a concert whilst reading the programme notes, for example, detracts from the listening experience. Not only does the auditory brain no longer have your undivided attention, your ears may also be working less effectively. Specialised “hair cells” in the inner ear amplify quiet sounds, making them easier to detect. These amplifiers, which are very sensitive to damage by loud sounds, may provide less amplification when your attention is divided, literally turning the volume down.
Use your eyes. One of the main reasons you can hold a conversation at a noisy party is because understanding speech is as much about looking as listening. Watching what others say contributes to the classic “cocktail party effect” in which watching the lips move makes what is being said easier to hear. Similarly, watching a concert orchestra raises your level of participation – you can use your eyes to follow the musical discourse as it passes from strings to wind and back again.
Cancel your flights. Seated over the wing on a long-haul flight, you become aware of an unbearable drone, the noise of jet engines revolving thousands of times per minute. Outside the aircraft (not recommended) jet noise can reach an ear-thumping 120 decibels, literally enough to shake the hairs off your hair cells. Inside, things are not so bad, but the low-frequency components in particular make it through the cabin walls (see bedsits passim), and the temptation is to crank up the volume on the in-flight entertainment system. Don’t. Instead, invest in a set of noise-cancelling headphones. Costing less than the latest iPod, noise-cancelling headphones continually measure the spectrum (range of sound frequencies) and intensity of cabin noise, and add “anti-noise” – an inverted copy of the noise – to cancel the sound within each headphone. Your brain has a similar noise-cancellation system that works by comparing the mixture of sound reaching the two ears, cancelling some of the noise and leaving the signal more audible.
Go on a noise diet. Going clubbing tonight? Then try to limit your noise intake during the day to a minimum. Noise at work is strictly regulated; no more than 80 decibels over 8 hours; for every 3 decibel increase the safe exposure time is halved. Noise at play is unregulated, and with sound levels in the average nightclub exceeding 100 decibels, you get your daily noise dose (accompanied by a bad dose of tinnitus – “ringing in the ears”) in less than half an hour. By accumulating noise damage in our early years, we risk degrading our listening experience in later life. Most deaf and hard-of-hearing people find listening to music difficult – melodies are hard to follow and the quieter stretches absent altogether. For cochlear-implant users, generally those with profound hearing loss, music resembles nothing so much as a record (remember those?) being played backwards.
Don’t smoke! In a recent study, researchers found that subjects who smoked during adolescence, or those whose mother’s smoked during pregnancy, showed below average listening abilities. When asked to distinguish between a word and a “non-word” (a nonsense utterance), smokers were less able to assess lexical content (whether the word made sense or not) than non-smokers, taking longer to make a judgment, and making more errors. Brain scans revealed that nerve fibres thought to play an important function in “active listening” were abnormal in these subjects. Interestingly, subjects with amusia (“tone-deafness”) – the inability to recognise musical tones or rhythms – share some of these abnormalities in brain structure with smokers, suggesting that the ability to follow a melody might also be impaired by exposure to nicotine during development.
Professor David McAlpine