Resonance of the Human Ear Canal

Have you ever wondered why the sound of nails against a chalkboard is so irritating? It has to do with the acoustic resonance of the human ear canal.

The auricle (the outer part of your ear) and the ear canal (the passage down to the eardrum) serve not only to collect and funnel sounds, they also serve to amplify sounds. The ear canal, specifically, amplifies sound in the high frequencies (for an adult, typically in the region between 2000-4000

Hz). The exact amount of amplification, the acoustic resonance, is particular to the individual and depends on the length, volume and curvature of the canal.

Ear canal resonance plays an important role when it comes to protecting our ears from loud sound. Anything placed inside the canal (a foam earplug for example) interferes with ear canal resonance. A foam ear plug does an adequate job of protecting our hearing; however, if one wishes to protect the ear and preserve the quality of the sound, ear canal resonance must be maintained. There are a couple types of earplugs which can help maintain ear canal resonance: an off-the-shelf version (ETY plugs) and a custom version (e.g., ER 15s). The ETY plugs make sounds quieter while replicating the frequency response of the average ear canal. The custom ER 15 earplugs require ear impressions and use a specialized filter to maintain the exact resonance of an individual’s ear canal. The acoustic buttons are available in different levels of attenuation (e.g. ER 9s, 15s or 25s). The custom plugs have the additional advantages of retention, comfort and reusability. I use my pair of ER15s during long road trips as the road noise requires me to turn my music up to levels that would otherwise damage my hearing. I also wear them while mowing the lawn, on an airplane and anytime I listen to music and do not have control over the volume.

Back to the chalkboard…..it turns out that the frequency of the sound of nails against the chalkboard is very similar to average ear canal resonance. So, a loud annoying high frequency sound is made even louder and more annoying by our own ears!

Terence Miranda is a Doctor of Audiology and the owner of Resonance Hearing Clinic

SEPTEMBER ART EVENTS LIVING IN LOCKDOWN ARTFUL REFLECTIONS ON THE PANDEMIC September 23 - October 21

ALSO ON: Until September 19: Warmland Calligraphers, Cowichan Valley Camera Club September 16 Speaker series September 24 ArtBubble@2

2687 James St, Duncan (250) 746-1633 I cowichanvalleyartscouncil.ca

Trial By Fire Pottery Studio 2 Week Wheel Classes

www.trialbyfi repottery.ca I 250-710-8758 14 www.trialbyfi repottery.ca

How are you? In the midst of a pandemic, that innocuous question gets more interesting answers than the usual “Fine.” For many people, even if immune systems and general fitness are not compromised, there is a strong sense of anxiety about what’s ahead for us and our families.

One popular way to calm down is getting outdoors. Hiking in the forest (or “forest bathing” as it’s called, from the Japanese “shinrinyoku”) has been proven to improve blood pressure not to mention toning your legs.

Art – creating it or just looking at it – is another antidote to our worrisome situation with huge benefits for mental and physical health. We’re also in need of community.

On September 8, the Cowichan Valley Arts Council will offer both art and community as it reopens the front doors in the Cowichan Community Centre. The Cowichan Valley Camera Club show and Warmland Calligraphers have been held over until September 19. Then September. 23, we open Living in Lockdown, a fascinating artistic reaction to the current Covid-19 situation – with painting, sculpture, mixed media and more.

Once again we can welcome small groups (and if circumstances change, we will offer more programs online). The fall speaker series, kicks off Sept.16 at lunchtime with an entertaining slide-talk on achieving realism with a limited palette, by local Federation of Canadian Artists member Phil Robinson.

Another new monthly event is ArtBubble@2. Drop in to the CVAC Studio on September 24, (2 – 2:45 pm) for a lively discussion of four wellknown paintings – this month from the Impressionist era.

We guarantee you will feel better after our brand of art immersion whether it is strolling through the galleries or listening to a stimulating talk.

Susan Down is managing director at CVAC

It’s streamlined, fast, and easy to get around in, and…

No, we’re not promoting the coming year’s model of a sporty car, we’re talking about the vehicle that gets people in the Chemainus Valley connected to the arts events and activities that make this such a

great place to live: CVCAS.ca. And in case you hadn’t noticed, the Chemainus Valley Cultural Arts Society’s updated website has a new domain name. We’ve moved from .com to .ca, a place that feels closer to home and nearer to our hearts.

Kevin Brooks of Versa Sign, who first brought the CVCAS online in 2010, and has managed its internet presence ever since, guided the transition through the technical hoops during the remake. “Thanks to Kevin we have an established online audience that will follow us to our new homepage,” said CVCAS President Bev Knight. emailing communications@cvcas.ca. At the heart of the site is cvcas.ca/events. “We’ve opted for a calendar that is easy to use, and gives visitors all the information they need to find what they’re looking for and mark their own calendars,” Spence said. An online form, accessed from a subThe .ca remake was carried out by the CVCAS Communications Committee, which would very much like to hear from visitors how well the site is working, and how it can be improved. “We haven’t gone for glitz and flash, what we wanted was a site that’s clean, pleasing to the eye, and highlights artists in all genres,” said Communications Committee Chair Craig menu to the events tab, makes it easy for organizers to submit calendar items. The main menu reflects an expanding role for the CVCAS in the Valley, linking to established pages like Music and Rainforest Arts, but adding Literature and a Collaborate tabs to the mix. There’s lots on the site to discover about what the arts has to offer people in the region. Spence. One link Knight hopes people will click “We wanted to make it easy for people to get involved with the arts in Chemainus.” You can let us know if we’re succeeding by is ‘Join us’, located on the homepage Notice Board. It takes visitors to cvcas.ca/ membership. “You can join the CVCAS online by filling

The Clay Hub Collective out a quick form and making your

Open with payment with a click,” she said. “By

COVID-19 measures joining you will get to know what’s

Now accepting happening in the new members and Valley, and how you planning for fall classes can support the arts here.”

Check our web site for current info www.theclayhubcollective.com

www.craigspence.ca