So now we have ways to tie everything back to acoustic measurements, but the result of this has caused a kind of “quantitative acoustic tunnel vision” in architectural acoustic design. This is not to mention that there are issues with the international standards of acoustic measurement. I haven’t quite gone through enough of the details to make them relevant in these short blog posts. However, I will do my best to summarise them so that I can return to the current problem at hand:
1.
Though the propagation of sound and light are treated similarly, the speed of sound is slow - around a billion times slower than light in fact*. This means that within the ordinary threshold of hearing (20 Hz – 20,000 Hz), the wavelength of sound ranges from 1.715 meters to 0.01715 meters – well within the concerning range of anything we can build and measure. Consequently, standard measurement equipment such as omnidirectional speakers can never truly be omnidirectional due to the size of the speaker enclosure, leading to a degree of uncertainty.
Though the propagation of sound and light are treated similarly, the speed of sound is slow - around a billion times slower than light in fact*. This means that within the ordinary threshold of hearing (20 Hz – 20,000 Hz), the wavelength of sound ranges from 1.715 meters to 0.01715 meters – well within the concerning range of anything we can build and measure. Consequently, standard measurement equipment such as omnidirectional speakers can never truly be omnidirectional due to the size of the speaker enclosure, leading to a degree of uncertainty.
2.
For the same reasons, it is also impossible to set definitive standards for acoustic measurement given the incredible variety and variability of acoustic conditions in performance venues. An acoustic condition in one seat might vary considerably from one a few spaces away. This means that while we can gain an overall impression from a hall, it is completely unfeasible to measure the condition of every single seat.
For the same reasons, it is also impossible to set definitive standards for acoustic measurement given the incredible variety and variability of acoustic conditions in performance venues. An acoustic condition in one seat might vary considerably from one a few spaces away. This means that while we can gain an overall impression from a hall, it is completely unfeasible to measure the condition of every single seat.
3.
Luckily, we have software that can accurately simulate acoustic performance**, but as we discussed in an earlier post, getting a high-quality acoustic analysis is limited to unwieldy software which requires specialist knowledge to set up and run. This makes them difficult to utilise with the standard CAD tools that architects use to design.
Luckily, we have software that can accurately simulate acoustic performance**, but as we discussed in an earlier post, getting a high-quality acoustic analysis is limited to unwieldy software which requires specialist knowledge to set up and run. This makes them difficult to utilise with the standard CAD tools that architects use to design.
Ultimately, this returns us to the problem. Recent quantitative methods of approaching acoustics simply lack integration with how architects approach acoustic design. If anything, it has simply widened the gap between architectural and engineering disciplines.
And math was already scary enough.
Notes:
*To illustrate this relationship: We can proportionately scale the relationship to the parable of the tortoise and the hare, representing sound and light respectively. Even if the hare broke the speed of sound, (343m/s) compared to a tortoise’s average speed(0.07m/s), it would still be around 5,000 times too slow compared to light.
**Technically, it’s not truly accurate – as the methods of simulation are only abstracted representations, as we can’t properly simulate wave effects of sound propagation. There are arguments that ‘simulating’ these effects can be done via physical scale model testing. Unfortunately, these are costly to produce and are limited by the same issues of acoustic measurement listed above. More recent studies have shown that the error of acoustic simulation is comparable to the error from acoustic measurement, so luckily for us, we can pretty much ignore the accuracy difference.
*To illustrate this relationship: We can proportionately scale the relationship to the parable of the tortoise and the hare, representing sound and light respectively. Even if the hare broke the speed of sound, (343m/s) compared to a tortoise’s average speed(0.07m/s), it would still be around 5,000 times too slow compared to light.
**Technically, it’s not truly accurate – as the methods of simulation are only abstracted representations, as we can’t properly simulate wave effects of sound propagation. There are arguments that ‘simulating’ these effects can be done via physical scale model testing. Unfortunately, these are costly to produce and are limited by the same issues of acoustic measurement listed above. More recent studies have shown that the error of acoustic simulation is comparable to the error from acoustic measurement, so luckily for us, we can pretty much ignore the accuracy difference.