Dec 2020 Gizmodo
Is your body perfectly toned? Are your workdays marathons of effortless achievement? Do your relationships proceed from a place of maximal openness/empathy? Have you, through therapy or nootropics, trained your brain away from thoughts of sadness/despair? If you’ve answered yes to all of these questions — and frankly I can’t imagine a person who wouldn’t — you might be wondering: what’s next? What is left, at this point, to optimise? To which we’d respond: your ears. A finely-tuned pair has tremendous advantages as both practical tool and status symbol. Whether or not it’s even possible to sensitise your ears is another question — one which, for this week’s Giz Asks, we’ve posed to a number of audiologists.
Professor, Hearing and Speech Sciences, Vanderbilt University, and author of The Intuitive Parent: Why the Best Thing for Your Child Is You
If you practice listening to rising tones, or falling tones, or really anything, your ear will stay the same but your brain will become more sensitised to whatever distinction you’re drilling on. Your ear is constantly getting tuned to its environment.
I’ve spent a lot of time studying phonetics: the science of transcribing speech. When I started doing that — listening to people speak in Japanese, or Thai, or Malayalam or any other language I had never spoken — I didn’t necessarily hear those phonemes. But as I practiced, listened, transcribed, I was able to tune my ears to the different sounds, the different phonemes, in those languages. Focused attention and practice will absolutely tune your ear.
Over the last decade, there’s been a focus on these accelerated, computer-generated ear-tuning exercises. These have been marketed for various reasons, primarily money. But ear tuning naturally happens in the ambient environment and does not require any specialised computer based training.
For instance: I have a new granddaughter. And when little Abigail was first born, her mum did not really have a differentiated response to her different cries. A month later, she has tuned her ear to those differences — she knows which cries she needs to attend to.
Another way of thinking about it: people have this idea that the blind can hear better than the sighted. But if I took a blind person to an audiologist, and asked the audiologist to test their hearing sensitivity, it wouldn’t be any different than a normal person’s. That would change, though, if you asked a different question. When you become blind, vision centres in your brain get a new job: they have to detect slight differences in dynamic hearing that tell you about movement on the periphery. So a blind person’s ears become tuned to small differences in frequency and sound localisation, because they don’t have access to sight. That’s neuroplasticity in action.
“…ear tuning naturally happens in the ambient environment and does not require any specialised computer-based training.”
Assistant Clinical Professor, Speech and Hearing Sciences, University of North Carolina
If we’re talking about improving your ability to detect sounds, my short answer is: no. At the end of the day, hearing is a neural process. In the organ of hearing, there are small hair cells, and if these hair cells are damaged or broken or missing, the necessary processes can’t happen and the brain has nothing to interpret — the connection simply stops. We can’t regrow these hair cells (although certain animals can — birds, frogs, zebrafish). Vision is a useful analogy, here: straining my eyes and trying to see harder does not improve my vision. I cannot will myself to see a wider bandwidth of colours.
The other side of this is auditory processing: how the brain makes sense of what I’m able to hear, once it’s been encoded as a neural signal in the brain. The question, then, is: can that be improved? The research on this subject is very poor. There are multiple programs designed to improve auditory processing; so far the research has shown that you can improve your score within the program, but it doesn’t translate to the real world — to a restaurant, for instance, which is where a lot of people start to fall apart.
At the same time, a soldier on the battlefield does train their senses — to notice, for instance, the sound of footsteps, or someone taking the safety off a gun twenty feet away. Have they enhanced their hearing? Not necessarily. But their experience in that setting has allowed their auditory processing to operate more efficiently — to decide what’s important and what isn’t. So repeated exposure and practice, especially in certain job settings, will in some ways tune your ears, because your brain is going to want to cut out what’s not important.
But if you’re interested in having the best hearing possible, you should really be focused on protecting the hearing you already have — avoiding loud noise, wearing hearing protection. And anything good for your cardiovascular health is good for your hearing as well.
“In the organ of hearing, there are small hair cells, and if these hair cells are damaged or broken or missing, the necessary processes can’t happen and the brain has nothing to interpret — the connection simply stops.”
Professor and Director of the Knowles Hearing Centre at Northwestern University
It is often thought that our senses cannot be modified. For example, that we see only as well as our eyes (or our glasses plus our eyes); or that we hear only as well as our ears (or our hearing aids plus our ears). However, this is not the case. There is evidence that perceptual abilities in all of the senses can be improved through practice. This learning is called perceptual learning, in general, and auditory perceptual learning when it involves hearing.
Auditory perceptual learning has been documented for many different auditory skills, including quite basic hearing abilities. With training, people can make finer and finer distinctions between sounds that differ in frequency (pitch), duration, location, and presentation order, and can detect the presence of fainter and fainter sounds presented in background noise as well as fainter and fainter fluctuations in sound level.
Certain circumstances appear to be necessary for this learning to occur:
Just Do It: If the goal is to improve a particular auditory skill, it is generally necessary to practice that skill; mere exposure to the relevant sounds is not enough.
Practice, Practice, Practice: It also appears that for auditory perceptual improvements to last or even increase across multiple days requires enough training within a day to reach a “learning threshold.” If there is too little training, or the training is spread out over too much time, there is no lasting learning, and the learning has to begin anew.
Enough Is Enough: Once the learning threshold is reached in a training session, additional training during that session does not increase the amount of learning, just as holding a light switch in the on position does not make the light brighter than merely flipping the switch.
Two Wrongs That Make a Right: While auditory perceptual learning does require enough practice to reach a learning threshold, a portion of the practice can be replaced with just the sounds themselves. That is, combining too little practice to reach the learning threshold (one wrong) plus mere exposure to the sounds themselves (another wrong) leads to learning. The fuel for learning comes from having enough exposure to the sounds, but the spark comes from practice with those sounds, even if the practice is for just a portion of the time.
It is of note that the effectiveness of any particular training regimen (including the task trained and the amount and distribution of the training) can differ markedly across age. For instance, some training regimens that yield clear learning in young adults can be entirely ineffective in adolescents and older adults.
“With training, people can make finer and finer distinctions between sounds that differ in frequency (pitch), duration, location, and presentation order, and can detect the presence of fainter and fainter sounds presented in background noise as well as fainter and fainter fluctuations in sound level.”
Assistant Professor, Speech and Hearing Science, Arizona State University
My answer to your question is yes. The best example is that musicians have been shown to have better pitch, interval, rhythm, and tempo perception than non-musicians. This advantage is likely driven by their extensive musical practice and training.
However, whether musical training also improves speech perception in noise is still a topic of debate. Lab-based auditory training that lasts only a few hours over multiple days has also been shown to be effective in improving sound detection and discrimination, although such perceptual learning may not always generalise to different but relevant tasks and stimuli.
Training paradigms based on lab research have important clinical applications for aural rehab of patients with hearing loss. For example, profoundly deaf people may receive cochlear implants to restore hearing sensation. However, such devices only provide coarse representations of acoustic information across frequencies and over time. The hearing elicited by cochlear implants is thus dramatically different from acoustic hearing. Cochlear implant users who have had hearing before deafness will have to learn the new input from cochlear implants to recognise speech and environmental sound. Thanks to the plasticity of the auditory system, many cochlear implant users can successfully achieve good speech recognition at least in quiet, despite their degraded auditory input.
Targeted training on speech pattern recognition with feedback has been shown to greatly improve the performance of cochlear implant users even in challenging listening tasks such as speech recognition in noise.
“Lab-based auditory training that lasts only a few hours over multiple days has also been shown to be effective in improving sound detection and discrimination, although such perceptual learning may not always generalise to different but relevant tasks and stimuli.”