IT challenges senses

Can you hear sounds with frequencies higher than 18,000Hz? Looking at an image, can you distinguish dots that are smaller than 0.02mm? Is there any point developing sound and image devices that exceed what the human senses are capable of hearing or seeing, devices which resolution is higher than our own? The industry seems to enjoy pushing the limits beyond reasonable use. Is it just for the sake of selling more? Not necessarily.

In the best case the human ear perceives sounds up to 18,000Hz. Age and other factors alter this faculty, and a 50-year person will probably be able to hear only up to 14,000Hz or even less. As for sight, 0.02mm is considered as the smallest “object” a normal person can see, in optimum conditions.

Whereas manufacturers seem to have stopped pushing the sound limit in equipment a few years ago, still giving us more than we apparently need, there is currently a frantic race to make computer and smartphone monitors that provide stunning image resolution. When we thought high-definition was the ultimate goal a mere five or six years ago, several manufacturers now go for 4K (four times high definition) and even 5K (Apple’s latest iMac screen).

It’s a big debate and an endless one.

Some say that even if you don’t actually hear sound above 18,000Hz, you somehow “feel” it, maybe not in your ears but on your skin or in your bones, or some way…. This is not a joke but an authentic justification that scientists and researchers frequently give.

The same concept applies to photos, whether printed or displayed on a monitor. Even you if your eyes can’t exactly distinguish dots of near-microscopic size, your overall perception of what you are looking at will still provide the unexplained feeling of something better, more pleasant than the officially measured scientific limit, or resolution as it is also called.

The above concept may be true. It most likely is. I for one agree that superlative sound and image can be felt as being more pleasant, more enjoyable even if one may not be able to explain why in absolutely technical terms.

There’s however another reason, a very tangible one, why sound and image with apparently excessive resolution are useful, and of course it is because it’s all digital.

From the moment multimedia contents are in digital format, which is the only way to go today, they are bound to be processed, edited and modified in countless ways in software applications like Photoshop or SoundForge. Therefore, starting with files which resolution is as fine as possible makes perfect sense.

Because each single step in processing sound and image may reduce the quality, even if in imperceptible manner, going through repeated steps may in the end reduce the final quality, eventually bringing it at or under the human sense perception threshold.

Professional audio engineers like to work with sound files that are recorded at a resolution of 24-bit/192kHz. At first this may sound (no pun intended) insane for it is many, many times better than what the best ear can perceive. Because of the several processing stages however, where various digital effects like delay, equalisation, normalisation, compression and so forth are applied, the resulting file may in the end be just ok for the human ear, approaching the industry standard audio CD quality, which is a humble 16-bit/44.1kHz.

In photo processing, again, starting a major editing session on a picture where numerous Photoshop functions will be applied may reduce the quality of the photo you are working on. Which is why starting with an apparently extraordinary picture resolution makes sense. At the end of the session your photo will be brought down to ordinary quality. 

Besides, experience and 50 years of continuous IT innovation have shown us that there is nothing such as too much in the digital realm, be it speed, storage capacity or resolution.