Stereo in the wild.

[Paul Hynes]

I had an interesting experience this evening on my local beach. I took the family to cool down to after today’s heat, as we are not used to temperatures in the high 20’s here.

I sat in my deck chair with a nice glass of wine as the sun gradually fell to the horizon. The beach is over two miles long and, aside from us, there was not another soul on it all evening. It is such a privilege to have this environment all to yourself. It was very quiet and calm, with just the gentle noise of the swell breaking on the beach. My thoughts drifted to stereo perception as I listened to the swell. I had an incredible stereo perspective stretching for hundreds of yards in both directions, left to right. I was able to shut my eyes, and, just using my ears, locate the direction of each source of wave noise, and it’s distance, accurately across this vista. This was without moving my head to hone in on the sound source. It is amazing how adept our two ears and brain are at mapping out a three dimensional sound field. It reminded me how fastidious audio design has to be to create the illusion of three-dimensional reality.

It was a shame I did not take the camera, as, aside from the band of wave action caused by the ocean swell, the sea was calm with a view that touched the soul from the Isle of Barra in the South to the sunset in the West. The hues across the sky were incredibly varied. We even saw the light at the horizon move into the green spectrum as the sun dropped below the horizon.

Regards
Paul

[jandl100]

Wow, that sounds like a fab day out, Paul. :)

Yes, the ear/brain is very good at sorting out directional cues - I guess it comes from a reluctance on the part of our ancestors to be et by sabre tooth tigers, or something!

Things do get more confused and confusing in a concert hall / closed environment, though - with multiple reflections mussing up the directional cues.

[Paul Hynes]

Hi Jerry,

Seclusion is easy to find here, as there are not that many residents and there is a limit to the available tourist accommodation. For me it beats the hell out of living in the metropolises.

I have to admit that sitting on the beach in calm weather is rather like an anechoic environment, as the sand tends to break up reflections and absorb acoustic energy. Because of this there are no acoustic reflections to inter-modulate with the sound of the waves.

Generally we live in enclosed spaces and room interaction forms a significant part of the acoustic environment. That said I believe we are so used to this type of environment that we are able to live with it providing the room is not too reactive. Rather like the “cocktail party effect” we can hone in on a conversation and filter out the rest to some degree.

The perception of room reflections also depends on the time delay between the initial generation of the sound wave front and the reflection waves arriving at the ears, as well as the perceived direction of these sources. Short time delays are more confusing to the source wave front, as they mix with it if the path lengths are similar, and longer time delays become separate discrete events, as they arrive after the original wave front arrives. These longer time delays give clues to the size of the acoustic environment. Of course, trying to recreate the original recording acoustic in a much smaller environment can get very confusing as this additional acoustic competes with the recorded one and no longer sounds natural to us. It is possible to deal with room acoustic issues but it can get time consuming and expensive. It is also possible to control the dispersion of a loudspeaker wave front to avoid a number of room interactions. Equipment resonance effects also need attention, and so the list goes on.

Now how can I get my line source arrays down to the beach? On second thoughts that’s too much hassle in this heat. I think I will just go back and sit on the beach this evening and soak up the natural environment, as we have wall to wall blue skies again today. Better chill the wine, charge the camera batteries and take it with me this time. Maybe I will take the guitar too. Nope, that will just pollute the environment. Just the wine, local sourced hot smoked salmon and the camera. :)

Regards
Paul

[Puffin]

Paul your inbox is now full. Rob.

[DaveK]

Paul your inbox is now full. Rob.

Nah, it's not, he's just set it up that way so as he isn't distracted from his plan to visit the beach :lol: - and who can blame him? - I think he's got his and his family priorities sorted and good luck to the guy :) .

[northwest]

You have no idea how fortunate you were to have that sort of tranquility. Every time I try something similar a scrote shows up with his/her CHOONS at ten zillion watts from THE cheapest pair of headphones!

and ruins the moment.

Enjoy it while you are able.

[Paul Hynes]

The in box is full again so I have emptied it. You can send again now Rob.

We're getting some crap weather from down South at the moment so not on the beach.

Here are a few sunsets on the local beach from a few weeks back.

http://i700.photobucket.com/albums/ww7/paulhynes/Photo0304.jpg

http://i700.photobucket.com/albums/ww7/paulhynes/Photo0303.jpg

http://i700.photobucket.com/albums/ww7/paulhynes/Photo0320.jpg

That's why we are here Graham.

Regards
Paul

[WOStantonCS100]

I took the family to cool down to after today’s heat, as we are not used to temperatures in the high 20’s here.

I'll trade today's record high 43 C for your 20 C.

Nice pics. I'd go outside and take some; but, I think the camera would melt.

[dave2010]

I'm interested that Paul claims he was able to accurately place the waves in space. How did he know if his eyes were closed?

I've not tried this on a beach, but in a concert hall I've thought on occasions I could place instruments accurately, and sometimes with a strong conviction, the strength of which might depend on the hall. I did this with my eyes shut. When I opened my eyes the instruments were sometimes quite a way from where I expected them to be. In some venues the acoustics are so muddled that localising sound sources is more or less random, but I was surprised that even in halls which I thought were good, without visual clues accurate placement is not always possible.

It may also depend on the instrument(s) being played, and one's location in the hall. The Royal Albert Hall is famous for its echo effects, and sometimes that can be very weird. It can also disrupt the rhythm of the music being played, so that some music can sound twice as fast as it actually is!

In the end I think I've learned not to worry too much about this. If it sounds OK then just enjoy it, even if sounds are coming from the "wrong" directions.

[dave2010]

Paul

Re the photos - wow that really is deserted! I used to think I'd like it like that, but now I wonder if it'd actually be scary. A few years ago I went on a (replica?) whaling boat for a short trip - just a few hours. Obviously there were others on board, so no worries about absence of people. The weather was brilliant, very smooth sea. At one point the views and the sheer - hard to explain - 360 degrees of views on the open deck were very disorienting - and also beautiful. Perhaps that would have been terrifying if there hadn't been anyone else around. Maybe a few of us (humans that is) do experience this degree of isolation and detachment frequently (perhaps fishermen?) but most of us who live in urban or even semi rural enviornments don't.

Do you still get the distractions of passing aircraft or are most of the sounds in your area natural?

[Paul Hynes]

Hi Biff,

Wow. 43 C, I could not handle that nowadays. The high 20’s is an exceptional event here, and we found this was uncomfortable. I guess we are used to the generally cooler climate here. Having said that we often have higher temperatures than London during the winter periods as the Gulf Stream acts like a giant storage radiator for us as long as the prevailing winds are from the Southerly to Westerly directions. I sure hope global warming does not shut this down as some science is predicting. If this happens we will end up with a Scandinavian climate.

Hi Dave,

I think that the ears are capable of reasonably accurate placement of sound sources without the aid of eyes. It may be that this skill is honed with experience with the initial help of our eyes but I am sure it is there. Our ancestors would need this skill to survive at night in hostile environments. In the modern world there are so many sources of noise surrounding us, whether directly generated or reflected that it becomes more difficult to localise a sound source. This we get used to, and accept, as you have pointed out.

On the beach there was no wind and the sand both scatters and absorbs sound, reducing the direct interaction with any sound wave generated by the sea waves. These were small waves caused by the ocean swell but still clearly audible for a considerable distance. The sand dunes behind me blocked out any noise sources from further inland and the environment was very quiet, with the exception of the wave generated noise. The angle of incidence of the sea waves varied along the beach so it was relatively easy to localise the waves breaking by hearing alone. Ok, it would not be down to the millimetre, but I could turn my head to face the sound source, open my eyes and the breaking waves were directly ahead.

On one occasion I have been out for a swim with my lass and stopped where the water was chest high. Standing there together in dead calm water was an interesting experience, as we could hear nothing from the environment. One of my customers visited earlier in the year and commented that, when he and his wife went for walks on another beach on a calm day, he asked his wife if she could hear “it”. She said hear what? His reply was nothing. This peace and quiet is priceless to me.

This deserted environment is like paradise for me and I find the crowded environment of London scary. It depends what you get used to as you grow up. As a child, living in Hale, Cheshire, I used to go off on hikes around the countryside alone, rather than get involved with the usual childhood pastimes. When I lived in Cumbria I used to seek out the quieter areas for walking. Here it is easy to find solitude as you can walk all day in many areas and not see anyone.

We get aircraft noise at the most once or twice a day during the week, rarely at the weekend. This is from local twin prop flights between here and the mainland or inter-island. The plane lands on the beach on the Isle of Barra! Here is a view down the beach to Barra :-

http://i700.photobucket.com/albums/ww7/paulhynes/Easter2011013.jpg

Any international flights over the Isles are too high to be heard. An occasional helicopter passes, maybe every few weeks on average, usually from the emergency services or the military. There are man made sounds around, of course, as there are other people on the island. It really depends where you are how much of this you get. Sitting here typing this I can only hear the computer fan and the birds in the garden. That reminds me, I must re-build the computer to get rid of that noisy fan. It is surprising how small things like this can become intrusive in a quiet environment.

Regards
Paul

[Ali Tait]

Lovely place Paul, you are a lucky man.