Sleepless in West Seattle

I love a good mystery, so what better way to kick off Hummadruz than with a strange story that’s in the news right now: The West Seattle ‘Hum’. The Hum is a peculiar and annoying buzzing/humming sound that has been widely reported in the West Seattle area over the last week or so, but can be traced to nowhere in particular. It appears to be more noticeable at night, especially in the early hours where it is loud & persistent enough to keep residents awake. Comments on the West Seattle blog show just how widespread the phenomenon is, with as many explanations as there are commenters. The blog even features an audio recording of the sound, from Julie Schickling of the Highland Park area:

Audio recording of the West Seattle Hum (the ‘hum’ starts about 28 seconds in).

It sounds like some kind of mechanical device, and there are, apparently plenty of contenders in the district, from large fans at a steel mill, through power transformers to road sweepers and distant helicopters. If the comments on the blog are anything to go by, it varies in dynamic range from extremely quiet to so loud it can be heard even while wearing ear plugs. Surprisingly, aside from Julie, above, no-one seems to have thought to record it (evidently, the curiosity level of sound recordists in West Seattle is fairly low – if I lived there, my first thought would be to head out and get some evidence).

The Hum, it turns out, is not a recent phenomenon – the West Seattle blog ran a story on it back in April 2009, with some commenters claiming they’ve heard it in years preceding that.

If you’ve ever had any experience reading accounts of anomalous phenomena, you will at once recognize the tone of the comments on the West Seattle blog. There’s a distinct impression that all these people have heard something, but a niggling feeling that maybe they’re not all talking about the same thing –  or, at the very least, not experiencing it in the same way. This is one of the problems with odd and diffuse phenomena – it’s hard to sort the wheat from the chaff when it comes to making sense of reports. Human beings are generally poor observers in the best of circumstance and it’s never quite so obvious as when it comes to sound. And, predictably, just to muddy it all up a bit more, there are the pre-requisite fruit loops who think it’s ‘the earth trying to communcate with us’, or aliens, or some kind of government conspiracy – as if things can’t simply be mysterious without having an agenda.

To add to the confusion and puzzlement, the City of Seattle’s Department of Planning, although acknowledging the existence of the Hum, seems reluctant to commit resources to tracking it down. The official Noise Inspector’s reponse to the West Seattle blog’s enquiry about resident’s complaints says, in part:

We are complaint-based, so we rely on the public to notify us of their specific issue and the location of the source. It can be difficult to pinpoint a noise source, especially when you have changes in topography in the immediate area. However, we need to know the potential source location in order to respond with an inspection…. On this particular complaint, we would need neighbors to locate the source before we inspect.

Not quite so easy to do when the ‘source’ is reported from all across West Seattle. That’s bureaucracy for you.

Now, one thing I noticed while reading the nearly 200 comments on the West Seattle blog was that many people were willing to give the location where they heard the sound, and some included even more detail, such as the loudness and the direction from which the sound appeared, to them, to be coming. There’s a not-insubstantial possible database there. So, being the kind of intrepid person I am,  I plotted it, to the best of my reckoning. A commenter on the blog, Ben, had the same thought, and created a Google map of the reportings. I’ve taken my data, and his data and refined it all to reflect reported loudness and also a feasible direction of the sound.

Red dots show occurences of the sound that had geographic location information. Darker red shows louder sound, lighter red shows quieter sound, as indicated in the reports. Green dots are from Ben’s map. Arrows show perceived direction of sound, when included. Highland Park, where Julie Schickling made her recording, is southeast of center on the map. There’s an industrial precinct to the north, another to the northeast, an airport, and a lot of water around this whole district, including a large canal that runs right through the area.

Of course, this ad hoc survey can’t be taken as a proper experiment, as it’s a self-reported, self-selected sample with no controls, so it should be clearly understood that everything we might deduce from this data should be considered speculative. Nevertheless, I think we might be able to make some useful headway if we can keep our assessments rational.

The first thing that seems extremely obvious is that there is no real clumping around any particular area. From this I think we can infer that the sound source is not localized within the West Seattle region. That it can be heard widely down through the area, and that so many commenters find it hard to pinpoint an exact direction, tends to weigh against a particular culprit in a particular location (although something mobile such as street sweeping machines – suggested by a couple of commenters – would remain a possibility).

Significantly, all the directional information, when we have it in the comments (and on Ben’s map comments) tends to point roughly toward the same area: just south of the Eastern Industrial district (disclaimer: I don’t know Seattle at all, and I’m doing this all off maps. I am more than happy to receive additional information & correction from natives.). Now, this could mean that the sound really is coming from that direction, but there are some questions, if that’s the case: why don’t we see clumping closer toward that area, and how should we explain that most of the reports of the loudest occurrences are actually quite a way from that location? We need to consider, also, that psychologically (and logically) there is probably a rational reason to expect that commenters would determine that the industrial areas are responsible, because the Hum does sound considerably machine-like and industrial.

I want to note also that the convergence of the arrows seems to indicate a point that’s significantly to the south of the industrial precinct, to an area that appears to be a container ship loading yard (where, in fact, a commenter drove to attempt to ascertain the location of the Hum). The Lafarge Corporation, a gypsum and cement facility, is also here.

Some other salient points to ponder: the Hum seems to be mainly active at night (although not exclusively) and also seasonal toward spring through summer (although one commenter disputes that). In addition, it is not a consistent phenomenon. It seems to come in surges, the last one being back in 2009. Not only that, the Hum, it turns out, has been reported elsewhere in the area – to the West of Seattle across the bay, on Vashon Island. In this area it is known as the Vashon Island Hum and has a pedigree and history of its own. Vashon Island is certainly way too far away from West Seattle’s industrial areas or shipyards to be affected by the same sound. And yet, it would appear to be fairly similar in nature.

It’s all quite intriguing, as I’m sure you’ll agree.

Among all the speculations and hypotheses on the West Seattle blog there are a few comments in particular that really piqued my interest:

‘Or, maybe it’s just ferry boat noises that can carry quite a ways’ ~ says Toby Getsch

‘My bet is on ship engines, possibly the container ships tied up in port. Could also be the ferries. I have kayaked around the port several times to realize the “hum” I’ve heard from my open bedroom window, since moving here in 95, has the same tonal qualities as the container ships’ ~ said Matt Durham in 2009

‘I’m familiar with this noise too and think it is coming from the sewers. Next time you hear it go to a storm drain and see if it is louder’ ~ said mmd.

‘What’s weird is it sounds loud inside and when you walk out it seems quieter’ ~ said DRW (and was not the only one to observe this)

‘Now that I listened to the clip I recognize the sound. … I always thought it was coming from the water’ ~said tp.

‘Reminds me of a didgeridoo…’ ~ said steph

All of which might be pertinent to a rather surprising conclusion from some researchers from Washington University who suggest a remarkable explanation for the West Seattle Hum: the Hum is produced by a fish. Specifically, they say, it’s the mating call of the Midshipman fish.

Indeed, that doesn’t faze one commenter who seems to be speaking with a fair degree of certainty:

‘It’s the midshipman fish. Happens every time this year. Not sure why it’s more noticeable this season—anything from a few new buildings to greater humidity could contribute to the sound carrying farther. But it’s the fish’ ~ declared J.

A fish? Really? Is that even possible? Well, what does a Midshipman fish sound like?

Whoa. OK, well, that is surely a plausible match for the sound recorded by Julie Schickling. Factor in some resonance & phasing and that is a credible fit. The US public radio outlet NPR also has a story on midshipman fish in which you can hear a lot more of the sound.

The Wikipedia entry on midshipman fish tells us that:

Typical Type II male calls are divided into: short grunts that last for milliseconds or are produced in a series of grunts called a “grunt train,” mid-duration growls, and long duration advertisement hums that can last up to an hour.

Commenter Carol on the West Seattle blog describes the sound she hears like this:

‘Hum is really loud now and it is mixed with a chugging sound interspersed with a tonal whine. Sounds like a construction project. This woke me up’ ~ said Carol

Now that’s a pretty damn good description of the sound in the video and the NPR piece – bit of a shame Carol didn’t have her iPhone to hand. A second commenter also hears a similarity:

‘I always assumed it was the steel plant. However, the recording of the fish sure does sound a lot like that hum’ ~ said West Seattle person

The Midshipman fish is native to the West Coast of the USA, and is quite common, especially in the coastal waters north of Oregon. The Red Orbit Reference library entry on Midshipman fish tells us that:

Mating in Midshipman fish depends on auditory communication; males during the breeding season broadcast a sound usually described as a hum, generated by rapid contractions of the muscles in the swim bladder. The sound can be kept up for up to an hour, and is loud enough to be heard by (and to puzzle) people on nearby land and houseboats; the hulls of the boats tend to amplify the sound to sleep-disrupting levels.

But the fish explanation is not going down well with the folks of West Seattle. It evokes a surprising amount of scorn on the blog:

‘Fish? Get real! The sound I think we’re talking about is mechanical: a very large engine, pump, centrifuge or something like that’ ~ said Bryan Hollister.

The sounds of the Midshipman fish seem extremely mechanical – even electronic – to my ears. If the Hum everyone is hearing is the sound that Ms Schickling recorded, there certainly is a similarity to the fish sound.

‘Anyone who understands the basics of energy transfer has to simply laugh at this “fish” theory. It would take a HUGE amount of energy to create a sound loud enough that it could be heard all over West Seattle and further, even if it was directly emitted from a land-based source’ ~ opined Jason.

Ah, yes Jason, but for anyone who understand how sound works, this does not seem nearly as far-fetched as you seem to think. For starters, your argument is largely self-defeating: if you require that the sound needs a huge amount of energy – assuming it comes from a human made facility as I think you must be implying – then it would be a relatively trivial task to locate it: just head toward the direction in which it seems loudest. The very fact that the directional source of the Hum seems to be, according to the blog commenters, extremly difficult to ascertain, says immediately to someone with training in sound that the major issue is not one of decibels.

Certainly, the sound is loud enough – that’s obvious. But really, to carry across an area like West Seattle, the generating source does not need to be as loud as you might expect, if conditions are right, and if you factor in some other circumstances. One thing we sound people would consider is the powerful force of resonance. You know that effect you get when you run your finger around the moistened rim of a wineglass? That’s resonance. Resonance is a sympathetic vibration that can, and does, amplify a sound quite considerably. Almost anything may act as a resonator, but typically, objects containing a mass of air work best. Think of a guitar body, or a drum. Resonance can have profound effects.

So. Since this post has become rather longer than I’d anticipated, I’m going to break it there and follow it up in the next, where I’m going to propose three  explanations for the West Seattle Hum. I’ll tell you right off the top, I’m favouring the fish.

I wonder if you can anticipate my logic?

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5 thoughts on “Sleepless in West Seattle

  1. Pingback: Fish or Foul or Fantasy? | Hummadruz

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