Light for listening – and why the moon is gold

National Deaf People Week

Maybe you’re one of the 13% of the adult population in the US affected by hearing loss (the percentage is much higher among men) – Quick Statistics About Hearing, Balance, & Dizziness, Declining Prevalence of Hearing Loss in US Adults Aged 20 to 69 Years. Or perhaps you live or work with someone who is.

If so, this week- and this post – is for you.

But what’s sound and hearing got to do with light and sight?

The nerves and networks that link your eyes and ears to your brain are intimately linked. Approximately four out of ten deaf children have some problem with eyesight and that connection continues into older age – Association Between Vision and Hearing Impairments and Their Combined Effects on Quality of Life.  If you suffer from tinnitus, you’re more likely to suffer from dry eye syndrome too thanks to extreme sensitivity in those connections known as  neuropathic hyperesthesia – Association of Dry Eye Diseases and Auditory Sensitivity.

Your hearing has a circadian cycle too: noise, along with light, is a critical ‘zeitgeber’ or time keeper – you’re around twice as sensitive to a sound at night, just as you’re much more sensitive to a blast of light after sunset.  Sleep is essential to recovery from damage to the delicate structure of the ear – you’re at increased risk of trauma from loud noises at night too – Time to listen: circadian impact on auditory research.

And yet people living with hearing loss are at far greater risk of insomnia (70% in one study) – Characterization of sleep among deaf individuals.

Lighting can’t heal your ears, but it can improve comfort and communication, reducing the stress and isolation that many people with hearing loss often feel.

Here are three suggestions summarised from the Deaf Strategies charity website, supplemented by guidance from Buro Happold and the National Development Team for Inclusion – Getting good environmental conditions for listening and lipreading, Technical Note: Sensory Friendly LED Lighting for Healthcare Environments.

1. Bright and diffuse lighting falling evenly on the speakers’ face.

Make sure the speaker is opposite the window or light source so their face, especially eyes and mouth are clear and sharp.

Keep checking and offer to more light as the conditions change, especially in the afternoon as the sun goes down.

2. Offer choice- position and location

Invite guests or colleagues to arrive early, choose their preferred seat and encourage them to switch places or even move to another space if the conditions aren’t right

If you’re standing in a group, a distance of 2-4 meters seems to be preferred- that way your guest can see your whole face and body language- but everyone is different, so just ask.

3. Cut out flicker, echoes and other distractions

Make sure the lights are steady – a flickering candle may be romantic but it makes it harder to see your face.

Avoid anything that distracts or blocks the speaker’s face. For example, in a restaurant, move the candle, bottles or flowers out of the way.

Choose spaces with soft furnishings because they reduce echoes, making it easier to hear speech more clearly, although some prefer an echo as it can help with orientation.

It’s not a ‘nice to have’ : Here in the UK, organisations have a duty to provide reasonable accommodations under the Equality Act 2010. In Europe, your rights are covered by a number of laws, a great summary is here – European Disability Forum, Your Rights in the European Union.

In America, it’s the Americans with Disability Act – The Americans with Disabilities Act (ADA) protects people with disabilities from discrimination.

Bottom line: these simple steps to make sure everyone can thrive don’t need to be expensive. A Job Accommodation Network  survey of over 700 employers – Money Mondays: The (Low and No) Cost of Reasonable Accommodations, found that 59% of accommodations cost nothing and 75% of those were judged to be very effective.

It might just pay off too. In a national survey (A national survey of consumer attitudes towards companies that hire people with disabilities, Journal of Vocational Rehabilitation 24, 3-9),

• 92% of Americans view companies who hire people with disabilities favourably
• 87% prefer to give their business to someone who employs people with disabilities, too.

Maybe it’s time for us to listen up –

Noise takes your eye of the ball 

Even if you can hear perfectly well, you’re still affected by sound, especially when you’re trying to concentrate. Some people are more sensitive than others, with an estimated 4% of us suffering from a condition called misophonia – where everyday sounds can trigger extreme emotional responses – Development and Evaluation of a Sound-Swapped Video Database for Misophonia.

Research suggests a clear link between noise and visual performance, not because your eyes are trying to follow or find the sound, but simply because it eats up processing power – The Effect of Noise Exposure on Cognitive Performance and Brain Activity Patterns, Auditory stimuli degrade visual performance in virtual reality. Plants and vegetation offer visual and auditory masking – pleasant visual barriers are more effective – Audio-visual interaction in perception of industrial plants – Effects of sound level and the degree of visual masking by vegetation.

That doesn’t mean we’re best in complete silence, just as the optimal visual stimulus seems to be close to the natural distribution of scales, colours and contrast in nature – A review of effects of visual environmental factors on interpersonal cognition and behavior: Focusing on brightness, color, and depth, the sweet spot for sound seems to be around 50 decibels, with a distribution of tones similar to natural sounds – Discovery of associative patterns between workplace sound level and physiological wellbeing using wearable devices and empirical Bayes modeling.

The Body Speaks 

As we drive towards low-carbon public buildings with strict lumens per watt limits, are we forcing healthcare providers to make choices that may hit the mark but miss the point?

Please join John Bullock and I at this event in partnership with Colin Ball, Deborah Burnett and Jim Benya at BDP on the 15th of October. Places are strictly limited so please register for the waitlist and we’ll release as many tickets as we can. 

Blue moon  

You may think the moon is blue – but take another look.

It’s really closer to orange – warmer than the sun, which makes sense when you think that moonlight is just sunlight bouncing off a grey rock spinning around in space.

We see it as cooler or even blue because of the way our eyes work:

In bright light, we’re using the cones to see colour – known as photopic vision.

When it comes to twilight and darkness, there aren’t enough photons to fire up the cones and we switch to mesopic and then scotopic vision.

That’s driven by the rods, which can pick up just a single photon spinning through space, triggering a blue-grey signal in the brain.

So that silvery moon is really gold.