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This page helps you to understand how The English Times works within your internet browser and uses your sound system.

To do these sound tests, you must have loudspeakers or headphones, connected and working. If your computer does not normally make sounds, these tests will not help you.

	GARY DENTON: HOLLYWOOD: USA

Your sound system and internet browser should let you play popular audio formats. Unfortunately, different browsers and browser versions do not do the same things, equally well.

To test your system, we need a short audio recording. So we asked Gary Denton to let us use two lines from one of the songs on his new CD.

On CD, the two lines, recorded at 44100Hz 16 bit stereo, need 1272K of memory. However, for this test, we re-recorded them at a lower quality, in mono. They now need 159K. Let's check that your browser can play PCM:

It should sound OK, and clear enough to listen to on your radio.

If you can't hear anything, check your volume setting. If the page jumps back to the top, or disappears, you need a newer internet browser.

Instead of asking Gary to fly here from Hollywood and record the two lines again, we electronically compressed the recording using a format which comes with Microsoft Windows, called ADPCM. It now needs 30K of memory, so will download faster. Let's check that your browser can play ADPCM:

Although the quality is not as good as the first recording, it still sounds OK, and clear enough to listen to as background music.

We then electronically compressed the original recording again, using another format which comes with Microsoft Windows, called GSM. It now only needs 12K of memory, so will download very much faster. Let's check that your browser can play GSM:

The quality is very similar to the previous recording. But, we've reduced the memory needed from 30K to 12K. This is over 100 times less than the original CD recording, so it will download around 100 times faster.

GSM is OK for general speech on the internet where fast downloads are important. But detail easily gets lost, and listening to speech for a long time would be tiring.

So, by reducing the sound quality, we can reduce the size of the memory it needs. This is OK for several seconds of speech, but for several minutes of music we need to use a different format. Let's check that your browser can play MIDI.

Why not take a break and listen to the Bampton Midi Orchestra playing the well-known part of the overture to the opera William Tell by the Italian composer, Gioacchino Rossini. They're ready to start:

Although it's a much longer piece of music than Gary's two lines, it only needs 86K. Compared to a CD recording, every second of MIDI needs about 500 times less memory.

If you can't hear anything, check your volume setting. If the page jumps back to the top, or disappears, you need a newer internet browser.

Copyright and Permission: Talking Technologies 2002

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