Anechoic

Adding to this, don't automatically include <wait for laughter> in your joke delivery. Make the joke - if it lands and the audience is laughing, you can pause until it dies down. If the joke doesn't land, you just move on and everyone will forget about it.

Which is the same constraint as pretty much any other physical item one might purchase. "reasonably a forever" is a reasonable description.

While converting a bridge to tunnel mid-construction doesn't happen, what does often happen is that design assumes a particular construction technique can be used, construction starts with that technique, and midway through it's determined that an entirely different technique is required. This results in a bunch of redesign, remobilization, etc. Just like with software, construction often does not survive first contact with reality.

These can be run in reverse as well, it requires CB custom electronics so it’s not something a lay person can do out of the box.

Source: I used to measure the “microphone” frequency response for a kiosk OEM.

Noise from data centers is a real issue, but Benn's measurements and analysis are not great (speeding up the sample rate to demonstrate frequency effects is just wrong, among other issues).

Count me in this group. I wound up buying the 13 mini right before it was going to be discontinued because I knew that would be the last small phone they would produce and I'm keeping it until it dies (or I can't get a battery for it).

https://reincubate.com/support/how-to/pair-lock-supervise-ip...

Again, it's not just "potential suspects" it's potential witnesses, or identification of potential casualties. I don't feel great about state actors of any type using facial ID, but I can think of any number of reasons why a FD might use it in the course of their duties, and I would much prefer they have it over the PD.

Part of the investigation is determining whether the event is actually a crime. I'd much rather have subject matter experts make the determination of arson vs. act-of-god rather than "every nail needs a hammer" police force.

You mean an expert in acoustics related to those areas? There are lots of experts and researchers. Take a look at the Acoustical Society of America, the Institute of Noise Control Engineering, and Council for Accreditation in Occupational Hearing Conservation for starters.

Penn State, University of Hartford, Purdue University, Michigan Technological University, University of Nebraska, Morgan State Univeristy, and Brigham Young University (among others) all have strong acoustics programs with research in a bunch of areas.

FWIW, I've also heard the same, but don't remember where off the top of my head. It's at least potentially true, but the conventional wisdom among acousticians/noise control engineering is that age-related hearing loss is mostly to increasing age rather than external factors.

Institute of Noise Control Engineering Digital library: https://www.inceusa.org/publications/ince-digital-library/ (papers older than 10 years old are available free)

Federal Interagency Committee on Aviation Noise: https://fican1.wordpress.com/findings/ (focuses on aviation noise)

Acoustical Society of America Lay Language Papers: https://acoustics.org/lay-language-papers/ (search for "sleep" -- the ASA has a full library of more detailed research but the documents cost money unless you're an ASA member)

World Health Organization guidelines on noise - https://iris.who.int/bitstream/handle/10665/343936/WHO-EURO-... (doesn't get into specifics on research on sleep, but does refer recommended limits to sleep disturbance)

NIH has done a bunch of research on sleep disturbance from noise, you would need to search through their library

edit (one more): TRB/National Academies https://nap.nationalacademies.org/search/?rpp=20&ft=1&term=n...

A lot of the stuff that posters are asking for have in fact been done, it just takes some digging through the research sites to find them. There's a lot of variation in the data, the hypothesis is that sleep sensitivity varies a lot based on various physical factors (age being a big one).

(Note that I agree with your larger point)

One discussion of this point can be found in an Indicator podcast[0] from a couple of months ago.

[0] https://www.npr.org/transcripts/1237470062

WilerHale and Jenner & BLock are two: https://www.npr.org/2025/03/28/g-s1-56890/law-firms-sue-trum...

Last I heard (which was admittedly about 10 years ago, things may have changed since then), the facility was struggling a bit. It's true that these types of testing facilities need quiet background noise levels for testing, but that can usually be achieved either through putting the facility in the middle of nowhere, or over-engineering the structure. NWAA obviously has both, but that results in increased costs. On the other hand, you have facilities like Orfield Labs and Microsoft's newest anechoic chamber that manage to be _very_ quiet while still located in relatively convenient areas. Plus many audio/speaker/acoustical products companies have their own facilities.

That said I'm glad NWAA is still getting press and I hope it remains a fixture for generations to come. We need more of these moonshots.

The implication is that we're talking about sound pressure level in air, therefore the reference pressure would be 20 µPa.

and for which frequencies?

Again, the implication is annoyance and in that context I'm looking at overall SPL in A-weighted decibels (A-weighted decibels, while not perfect, is reliably correlated with annoyance)

I think you don't really know

For the record I'm an expert [0] in acoustics and noise control. It's how I've made my living for the past 30 years. So yes, I really know.

or you would have specified

I wasn't trying to get into a detailed discussion here, but I'm happy to oblige for anyone that wants to learn.

as with most things relating to acoustics, the truth appears to be extremely complicated

Absolutely. That said, if you look at the link, the author mentions 8-9 dB of excess attenuation with 50 meters of intervening foliage. That correlates to about 1 dB of attenuation per 18 feet of foliage. Again, that demonstrates that a strip of foliage would do almost nothing to reduce sound levels. And for what it's worth, the phonemea the author is describing is not "absorption" - it's a combination of partial cancellation of the reflected/direct wave interaction in porous soil (same reason why snow covered ground makes things quieter) and refraction from leaves/trunks (which is why the foliage needs to be _dense_, otherwise soon waves travel through the gaps and provide no reduction).

[0] By "expert" I mean a) studied the subject as an undergrad at MIT b) worked for 30 years in the field, producing or contributing to several hundred Environmental Impact Statements in the USA, authoring/co-authoring a couple dozen papers and presentations including one peer-reviewed study, c) authored or contributed to acoustics guidance manuals for the U.S. Federal Transit Administration, Federal Aviation Administration and National Academies, d) have been admitted as an expert witness in acoustics/noise control in criminal and civil trials in seven states, e) have certification demonstrating noise control expertise [1], f) been recognized by my peers as having contributed to the field, g) have had research referenced by international researchers

[1] https://www.inceusa.org/board-certification/about/ (sample test questions available at https://www.inceusa.org/pub/?id=6FBAEF10-B2FE-1D7D-AFCA-55D5... if you want to see the type of acoustics knowledge that is tested.

A thin strip of foliage does (basically) nothing to reduce noise propagation. Dense foliage (meaning you can’t see anything through it or move through it) gets you about 1 dB reduction for every 10 feet of thickness.

[0] https://archive.wheel-rail-seminars.com/archives/2022/rt-pap...

Apple reversed that decision back in March [0] (expand "Why don't users in the EU have access to Home Screen web apps?")

[0] https://developer.apple.com/support/dma-and-apps-in-the-eu

https://crp.trb.org/acrpwebresource2/improving-intelligibili...

Not only is it common knowledge it's how drive-thru kiosks work!

Source: I used to test microphone/speakers for a kiosk OEM.

If Rome wrote an engineering manual, it would still be quite valid today.*

Considering many engineering standards from a few years ago are no longer valid, this is almost certainly not true.