How echo of speech travels

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Why someone talking may be easily heard.

Be it an open office or say, a restaurant, it is typical that someone elses’ talk – from a nearby table – is overheard.

Especially, in case the ceiling and / or walls are clean flat. The further away these surfaces, the longer the time of echo – the reverb time. Because of the longer travel of sound waves.

To mitigate the echo time, obstacles can be arranged in the main path of a Sound wave. Either absorbing obstacles, and / or path (sound wave) altering obstacles – diffusers.

In the ceiling, where normally there is sufficient space, absorbing plates can be hanged in a vertical position.

Picture of plates, hanged from ceiling :

Sketch of plates hanging from ceiling :

On the walls, where space is more limited depth-wise, diffusing panels is a food option.

Picture of diffusing panel, mounted on to wall.

As these type of solutions is utilized, the overall sound pressure – volume – decreases in the interior space. Therefore, no longer is each table competing to uphold a conversation – no longer difficult for friends at a table to hear eachother.

About CO2, Highlights from SLUSH2019

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Picked up from SLUSH and Swedish radio channel P1 news, 3rd week November.

We can agree there is a rise in temperature, around the globe. If in doubt, one has to be willing to PULL the information – to do ones’ own research.

Continue reading About CO2, Highlights from SLUSH2019

Recycling – an Ecological deed

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Continuing on my writing about the recent (15th March) youths’ demonstration – not having done their homework before marching against the government(s) – I thought I dig a bit deeper into Recycling. About what can be done against climate change.

At least give a peek into my personal findings of the state of the world.

Negative trends Continue reading Recycling – an Ecological deed

Youth demonstrating for climate change

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Call for a Change from Fossil Fuel

It is always good to experience / see the burning desire for change in our Young. Especially within the subject / matter of actions to stop climate change.

Reference made to the school-boycott’ing-youth within Northern Europe, earlier this week. Marching, demonstrating.

However, it seems this movement is largely based on the notion that adults are not in panic. Panic – defined as in – drop everything you are doing. Most of all, show that you are panic’ing. The notion that nothing has been done, or not fast enough.

So, what has been done? Or, what IS going on to stop climate change? Specifically, around burning less Fossil Fuel.

Trends of change

A few – in my view – negative trends :

1) increase of nuclear power plants. (Finland, France)

2) gases from home communities is not being recovered (caught). Yet.

3) increasing emission from food cooking, due to unclean burn process. (Asia, India)

A few – in my view – positive trends :

1) change to battery powered cars / buses / trains. (better air, more efficient use of energy)

2) catching of ship emissions at sea, harbour & coastal areas (suplhur, NOx, SOx, particles). Do google IMO 2020, and Wet scrubber.

3) biofuels and hydrogen are emerging, stronger every day.

4) gases from waste is being catched within the waste burning plants. Also burned.

5) nuclear plants are being decommissioned (Sweden). Decreasing in number.

6) increasingly more fuel efficient airplanes.

7) houses being built from wood. Multi-storey. Passing 18 storeys, as we speak. (Binding CO2)

8) more and more people understand how to start / keep fires burning clean. (home heating)

Of the above mentioned points, especially heavy vehicles and ships account for a huge amount of emissions – that would otherwise end up in the air breathed on land. Do google the amount of people that annually die due to lung-related diseases in your country.

Homework not done

From all of the noise made, I fail to have seen any evidence of ideas for change presented by the school-skipping young. ONLY a call for action. To the government(s). { perhaps I failed to catch something? }

It therefore seems that the youth haven’t done their homework. Starting with the Swedish young lady who started the call / cause by skipping school every Friday, in order to sit at the front steps of the Parliament (in Stockholm).

Don’t get me wrong. All ideas are welcome. The work together for a change must always live. In a democratic and peaceful way.

To catch media attention and scare people is not the way. Such as climbing the facade to lock yourself high up in the columns of the Parliament (in Helsinki) – wonder what the heart rate of the guards and inhabitants jumped to, as they witnessed / before they understood what the ‘attack’ was all about. Greenpeace tactics. This organisation must have though it was a brilliant idea. Plant treas instead? Naw, not fun. Hands get dirty.

Grass root level

Thus, do educate yourself and work (communicate, collaborate) for change. Don’t expect information to be pushed to you. It is allowed to pull information (do your research).

The governing bodies can only set the framework, rules of conduct. History has shown that the ‘real change’, the ideas for change, the inventions, happen at the grass root level!

And please do plan / go about it energy-efficiently. As a side note, I wonder how much energy and material was wasted / consumed in the name of the boycott. The media for sure got a good run for their money (= something to report upon).


About the author

Martin R.C. Andersson started out as a mechanical engineer, slowly developing a soft spot for project management – in which he worked for 10 years.

Although – at the time – having resigned from a corporate career within project management, that soft spot he keeps alive through a keen interest in room environment (interior) treatment.

By control of sound and light, looking to tweak for that noise-free listening… which should be a norm. Values silence, and now and then some solitude.

Thinks Mindfulness is a ‘state of being’ – when work gets done. When thoughts flow – without disruption – to reach either a creative state or complete whatever’s at hand.

When the outside world is tuned out, performance tuned in.
Feels best when Minimalism, Functionalism and Art come together.


#fossilfuels #C02 #greenpeace #IMO2020 #hiilijalanjälki

8mm projector conversion to LED

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From halogen bulb to LED

What if one could increase the lamp life 100-fold, and avoid all that heat – that would burn the film in case the film would stop running…


3 generations were seated to dig into a number of film rolls from my childhood, to travel back in time some 40 years. We got through 20 minutes of film, when the light bulb came to an end.

The projector – the patient

Fujicacolor 10M

Life expectancy is 25 hours, so having lasted since my childhood – that in itself was a lot of hours than the listed expectation.

Continue reading 8mm projector conversion to LED

3rd ‘acoustic’ wall panel finished

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Now finished with the 3rd sound mitigating wall panel.

Echo-mitigating, to be exact. Noise is sound categorized as pollution. Sound is air waves. Echo is air waves being reflected, usually from flat surfaces.

And this wall panel acts as a diffusor. Breaks the air waves apart. Each wave into many many smaller waves. The process is called diffusion.

Now I got caught up in technical digestion… This story is about how the third wall panel came to life :

  • A dedicated cutting table
  • Cutting the tower pieces
  • Gluing the towers together
  • Cutting the picture
  • Gluing the picture
  • 4 parts makes the complete picture

Continue reading 3rd ‘acoustic’ wall panel finished