There are some serious misunderstandings that reach me about the quality of sound systems in the classroom.

Unlike Hi-Fi systems where listeners are used to, and some obviously enjoy, booming bass sounds and higher pitched screaming guitars or the full range of an orchestra, the need to make the voice of a teacher intelligible to a classroom of young pupils requires very different sound qualities.

The human voice generates most of it's power between 100 Hz and 2 kHz, this is a tiny proportion of the full Hi-Fi range but unless consonants can be heard in this frequency range, speech becomes almost unintelligible. In Sound System Engineering by Davis and Patronis they state that “It can be seen why the telephone with it's limited response works so well as do small radios with well-designed 4”- 8” loudspeakers covering the range of 125Hz-5000Hz”

Comparing music on a Hi-Fi set-up with that played into a properly engineered classroom audio system, the classroom system will sound flat and the big mistake is to assume that the quality of the system is not good. This could not be further from the truth.

Speech intelligibility calculations and tests show that the articulation loss of consonants in speech (%AL_CONS) which is normally measured at 2kHz should not exceed 10% to 15%. The most important factor of the audio system for classrooms, is to have the correct frequency spectrum shape at 2 kHz. Many of the available sound systems ignore this in their design and would need some equalisation to correct these defects at 2 kHz.

So the simple answer is that a normal music amplifier system is unlikely to perform well for intelligibility in the classroom despite an untrained listener thinking that the boomy sounding base relates to a higher quality system

Our classroom audio systems are designed specifically for maximum speech intelligibility at 2 kHz in terms of frequency response, articulation loss and sound pressure levels and perform exceptional well at improving listening and as a result improved learning outcomes. Don't be fooled by those who offer to sell you under powered and poorly designed systems with booming bass !

David Edis-Bates C.Eng MIET

CEO EdisAV

Two brilliant articles by Terry Freedman

14 Ways To Make Your School Website Better

Let's face it: most school websites are pretty boring. True, some have improved a lot in the last few years, but they're mainly the exception that proves the rule.

Looking at most school websites is like taking a trip back in time. No interactivity, no sense of community, no updates for weeks, if not months.

In short, no life.

There are ways in which you can ensure that your school's website is not only vibrant, but stays that way.

Regard The Website As A Publishing Medium, Not A Technical One

This may seem a bit of a no-brainer, but in too many schools the 'powers-that-be' delegate the task of website maintenance to the Head of ICT. That's like delegating the job of producing the school prospectus to the Head of English, on the grounds that it uses words.

Regard The Maintenance Of The Website As A Collaborative Process

Why should only one person be responsible for generating the content, keeping it updated and publishing it? If several people were involved, and if all staff were expected to contribute to the site in some way on a regular basis (once every half-term, say), the website would almost look after itself.

Regard The School Website As The Website Of The School

The 'school' includes pupils, parents, support staff and even the local community, as well as teachers and the Principal. It includes more than the curriculum and sports activities. See the next point too.

Show What The School Is Really Like

School websites often talk about what a great job the school does, usually through a combination of lists of examination results and photos of people on a sports field or at a computer. Yawn. Why not have pupil bloggers on the website, discussing what they do and why, and what they like and don't like?

Why Not A Blog?

With that in mind, consider having a school blog rather than a website, or have a website which incorporates a blog. A blog can be updated quickly and easily, and lends itself to participation by allowing comments to be made on the articles posted.

You Can Go Further Than Articles

How about a school Social Community area in which parents can get into blogging and discussions? Obviously, it would have to be moderated, but think of the dividends in terms of goodwill and excitement.

Or How About A Weekly, Or Monthly, Opinion Poll To Engage Parents?

It doesn't even have to be about the school itself. A question like "What do you think of the new Vetting and Barring Scheme? would generate some interest, and may even provide some good ideas for the school. It should certainly give the school management a good idea of where parents stand on the issues involved.

Nice Target, Shame About The Approach

The main aim of most school websites is to attract new pupils. They have a corporate kind of aim, but not a corporate kind of approach. Most commercial websites give stuff away. It doesn't cost them much, but gives people the impression they are not just after your money.

How come I have never seen a school website that gives stuff away? For example, how about a downloadable sheet about keeping your child safe online? How about one explaining what the National Curriculum levels mean?

Don't Have A 'Latest News' Page...

... Unless you really are pretty sure that you can keep it going. There is little worse than seeing that the 'latest news' is three months out of date -- which it may be, given end of term exams followed by a long summer break.

Have A Publishing Schedule

It makes life a lot easier if you have a good idea of what you're going to write about and when. There are key times of the year, of course: reminders of holiday dates, and parents' evenings, for example. There are also key times of the week, such as setting the tone on a Monday morning.

Blog Ahead, If Possible

One of the features of a blog I now regard as a must-have is the ability to write a post and have it appear at some time in the future. It means that you can bash out a few articles all in one go when you have the time and energy, and set them to publish at the rate of one a day automatically.

Another handy feature, if you can get it, is one which 'unpublishes' articles.

Write Draft Posts

A blog post is referred to as a 'draft' if it has not been published yet. It's incredibly useful to be able to have articles written and ready to go live, but not necessarily automatically. Why? See the following point.

Be Forever Timely

Taking the above three features together, it is possible to write an article called, say, 'Big basketball match tomorrow: don't forget!', have it appear the day before the match, and then disappear on the day of the match.

As well as keeping the articles timely, and therefore relevant, it also paves the way for putting up two further articles: 'Basketball match: the big day arrives!', and 'Basketball match results'. This is where the draft articles come in. True, you can't write much detail about something that hasn't happened yet, unless your name happens to be Nostradamus, but you can write something which is almost certain to be true, such as:

'The basketball team looked resplendent in their kit as they marched out onto the pitch. Nerves? Maybe, but only their coach would know, and he wasn't telling!'

All you have to do on the day is take a quick snapshot, upload it along with a caption and a bit of text about the weather or something somebody said, and hit the Publish button.

Regard The School Website As Important

That means, giving whoever is responsible for putting it together and maintaining it or co-ordinating everyone involved some proper time to do it in. Or exemption from doing (some) cover/substitution. Or even a bit of extra salary perhaps?

14 MORE Ways To Make Your School Website Better

Around 18 months ago I published an article entitled 14 Ways to make your school website better. I took another look at the article over the weekend, and I think there is little I would change. Ning is no longer free, so perhaps were I to write the post today I’d suggest looking at this guide to the best social networking services for free alternatives. Other than that, I think it has stood the test of time pretty well, especially judging from a few people’s responses via Twitter.

 Nevertheless, there is always more we can do, and so here are 14 more suggestions for improving your school website. I do not for one minute suggest that anyone try to implement all of them! Regard these 28 points as suggestions from which you might select two or three to try out. If you can think of any more, please let me know, or leave a comment.

 SET UP A WIKI FOR PARENTS

It’s good to get parents engaged. In Building Parent Engagement in Schools, by Larry Ferlazzo and Lorie Hammond, the authors draw an important distinction between parental involvement and parental engagement. (Incidentally, I’ll be reviewing that book in the next edition of Computers in Classrooms, the free newsletter for educational ICT professionals.) Why not set up a wiki in order to learn more about parents’ suggestions for access to social networks in schools? Perhaps the wiki could be used for drawing up a code of conduct about cyberbullying.

 SET UP A SUPPORT FORUM FOR PARENTS

There’s still a lot of mileage in “old-fashioned” technology like forums. Why not experiment with a forum in which parents could ask questions of other parents? It would be interesting to see what sort of issues parents are concerned about, which they may not wish to voice to a teacher directly. It would need moderating of course – a job for one of the governors, maybe?

CREATE A FAQ PAGE

Still on the subject of parents, not everyone wants to trawl through the school prospectus to try to find out who to phone when their child is ill. These days, many people are used to looking through a Frequently Asked Questions page to find the answer they need, so that’s another way to get them coming, and returning, to the school website.

PROVIDE A LINK TO THE SCHOOL’S VIRTUAL LEARNING ENVIRONMENT

If that’s not possible or feasible, provide a parental login page, at least, from which they can access the forum, the FAQ page and the latest bulletin like “Sports lessons cancelled tomorrow” – the kind of thing you don’t necessarily want to share with the world at large.

SET UP A COMMUNITY NEWS SECTION

Many schools are hubs of the local community, so why not have a community news page? The local doctor’s surgery could put up notices, or supply them to the school’s web editor, about flu jabs, healthy eating tips and so on. Ditto safety tips from the police. An advantage of this is that the school can keep its website vibrant without having to provide all the copy (written material) itself.

SET UP A PHOTO GALLERY

This is another way of avoiding having to write stuff all the time. If your website platform allows it (most do), you can set up a page which links to a Flickr page. A snippet of code means that you can have a changing photo display without having to do anything manually once you’ve set it up – apart from uploading more photos every so often of course. You can seen an example of this sort of thing at the Writer’s Know-how website.

CELEBRATE ACHIEVEMENT IN THREE DIFFERENT WAYS

A page for examination and sports results.

A page for pupils’ work.

A page for pupil achievement, eg “Merit Award of the week”.

With any suggestions involving pupils, make sure the child protection guidelines are followed. And even then, I’d get the final seal of approval from a senior teacher if I were you.

USE MEDIA IN THREE DIFFERENT TO ENGAGE WITH PUPILS, PARENTS AND THE WIDER COMMUNITY

Set up a school YouTube channel.

Set up a school podcast.

Set up a school radio station.

These can involve the pupils – they should – involve the pupils, so there are other benefits from getting them to work together for a real audience and a real purpose. But do make sure these things are sustainable before you start, rather than announcing a weekly video bulletin, say, to great fanfare, and then allowing it to die after three episodes.

USE OLDER PUPILS

Kids don’t like listening to adults, but they often listen to other, especially older, kids. Advice on behaviour, studying, dealing with bullying are just some of the topics that could be addressed.

WHERE ARE THEY NOW?

How about a page which features ex-pupils? How are they getting on at their new secondary school, or university, or job? If you aim to update the page once every couple of weeks, ie twice per half term, you’d only need to line up about a dozen a year. And such a page might tell prospective parents more about the school than test results alone.

CONCLUSION

Hopefully this list has given you some food for thought. Not all of them will be possible, I realise, whether because of “political” issues, technical ones, or others, but perhaps they contain kernels of one or two useful ideas.

AUTHOR: TERRY FREEDMAN, EDUCATIONAL ICT CONSULTANT | WEDNESDAY, NOVEMBER 11, 2009 and MONDAY, JUNE 6, 2011

When choosing a touch screen, LCD or whiteboard the choice of aspect ratio can be a tricky decision. Aspect Ratio is one of the most misunderstood aspects of image display. Here are some tips and insights on how to make better choices.

Common aspect ratio standards are 4:3 and 16:9 but 16:10 is a new aspect ratio for projected images, which has come from the computer industry.

The fundamental issue is a common expectation that "if I paid for a screen of a given size, then I want my image to fill the whole screen." This is what has created the stretching and cropping modes built into TVs.

The classroom environment is probably the best illustrator of the problem. There may be document cameras of various aspect ratios, permanently installed computers of various aspect ratios, transient laptops of different aspect ratios, DVD or Blu-ray players of at least two aspect ratios, white boards, touch screens and possibly other devices... all with different aspect ratios

So key questions to aid the choice of aspect ratio selection are...

• What is the most common source that will be used?

• What is the most "important" source that will be used?

The answers to these two questions can provide the "best" choice of screen aspect ratio. Of course the trick is defining what is "important" for the user. Important could mean the source that you want to look the best. In a classroom where random content is most common, 4:3 supports the widest range of content. However if it is a classroom where many videos are shown then 16:9 would be the best choice to match video sources.

The design goal of a presentation system is to get the best possible image from the equipment and budget constraints. The aim has to be to select devices where every pixel of the source can be used.

While 16:9 is a video industry standard (as in TV, videos and movies). 16:10 has been adopted by the computer industry, where for the same width image you get a little more height. In the windows world, this added height actually gives space for the windows taskbar

16:10 was the logical upgrade from 4:3. It allows two printable pages to fit side by side in full screen. It also allows 16:9 content to be displayed along with a menu bar at the top (or bottom) enabling a single line of information or editorial.

A couple of years ago, wide-screen laptops were almost all 16:10 which gave the advantage of a bit more height. Now many of the latest laptops are 16:9, which probably comes more from the entertainment side of things to match a wide-screen TV.

The pixel count and ratio of the actual imaging element in LCD panels or DLP chips are:

• XGA (4:3) chip is 1024 x 768 pixels

• 16:10 is 1280x800 or 1920 x 1200

• 16:9 is 1366x768 or 1920 x 1080

(There maybe other less standard options, but these are the main ones)

You can manipulate the image however you want, but for true geometry and image quality... each pixel on your computer screen should have a corresponding pixel space on the formatted image be it on your Touch Screen, TV or whiteboard... so choose the aspect ratio to suit your most "important" source.

Very few speaker systems are designed especially for teachers in the classroom. Here are 6 tips for choosing a classroom active speaker system based on our experience and teacher feedback: 

Basic design

Active speakers designed with a built-in amplifier reduce the amount of cabling and the costs of equipment as well as being quicker and easier to install

Steel grille

Steel grilles, rather than more common fabric grilles, stop pupils from damaging the speaker cones with fingers, pencils or missiles so extending the life of the system

Adequate sound level for a classroom (>75dB )

The sound level should be at least 15 dB above normal classroom noise of around 60 dB at 6 metres ie the back of the class, so less than 30 watts is unlikely to be loud enough and if much more than 30 watts the cost of the system is likely to be too expensive (so aim for 15 to 20 Watts RMS per channel)

Easy to control

It may seem obvious but many speakers have controls at the back that teachers can't reach without climbing up a chair ! An accessible volume control and on/off switch at a sensible height is needed

Inputs for PC and DVD or other audio source

Shelf speakers and simple systems may only have one input - so you would have to re-connect every time you want to change the sound source. Two inputs are best for the classroom so that equipment is permanently connected.

Audible sound for voice

A wood speaker case and a flat frequency response is better than a sub-woofer amplifier system that accentuates the low frequency sounds, which is good for music but not so good for voice, especially for younger pupils who need to hear the teacher's voice clearly as their interpretation of speech is not as good as adults.

Useful links

Active speakers for the classroom