What could be making this sound?

[Muse]

http://bayfiles.com is another often overlooked uploading site.

I registered there today. Don't have anything to post yet, but imagine I will. Says there's a 5GB file size limit! That tooFiles.com site is free for <100MB (which should work for me most of the time), with paid registration <1000MB.

 

[Muse]

It's never occurred to me that it may vary with the temperatures/seasons. I'll keep this in mind.

I went outside yesterday afternoon and had a good listen at the property line. I'm sure it's coming from his house. Standing at the fence, about 30' from the back door of his two story house I'd estimate at 1600 square feet, the sound is a lot more complex than what I make out inside my house (i.e. in my bedroom). I hear the ~570 cycle tone in my house but outside it's got a lot more going on, I think a motor is involved and there's whooshing, churning, maybe some whistling, all that kind of thing. It almost sounds like what I'd expect to hear if a vacuum cleaner were on, but obviously noone keeps a vacuum cleaner on for hours at a time. I don't hear it right now and it's 3:45 AM. I have to wonder if it's a heating system. I'd expect to hear that kick on occasionally, kick off occasionally during the day, more on in the evening and at least some of the time during the night and early morning. It doesn't seem to have that pattern. It's persistently on for stretches with those short off moments ranging from 3-5 seconds to a minute or two. I have to think it's not there at all for hours as well.

Well, I have not noticed this sound since the last posts and it has occurred to me that it could indeed be a vacuum cleaner! This guy, when he starts up with his weed wacker (mentioned above) he goes at it for a long time, maybe 45 minutes. That makes a huge racket, and of course, it's outdoors, right across our common fence. I think he has a habit of vacuuming occasionally and he does this in long sessions, probably going from one room to another. The short moments when the sound is gone are the times he moves from one room to another, in all likelihood. He switches it off for a few seconds and then, "there it is again!" This is a little embarrassing, to have started a thread on this about something as commonplace and mundane as a vacuum cleaner, however I think I probably have the answer now, I figured it out a few posts ago without realizing it at the time! :\ Wow, I really thought I had a problem there, now not so much....

 

[Rubycon]

Could be a central vacuum. That would be louder outside. Typically the motor/collector can is mounted in a garage or area outside of the normal living space and the exhaust is outside. If the run of escape pipe is resonant the effect could be amplified, unknown to the homeowner but very audible at considerable distance outdoors!

 

[Muse]

Could be a central vacuum. That would be louder outside. Typically the motor/collector can is mounted in a garage or area outside of the normal living space and the exhaust is outside. If the run of escape pipe is resonant the effect could be amplified, unknown to the homeowner but very audible at considerable distance outdoors!

Seems plausible because I haven't noticed the sound getting louder and softer, which I would expect if a vacuum were being hauled from room to room. Very plausible!

 

[Muse]

I'm hearing it again tonight. Maybe someone's vacuuming again, I'm doubtful. I went outside to the property line around 7:30PM (there's still a lot of ambient noise here in Berkeley), and I made a recording that lasts 78 seconds. From around 40 seconds in to about 60 seconds in I held a funnel up to the internal microphone access point on the iRiver H140, but I'm not sure it affected the recording particularly. I held the plastic funnel close but was careful to not let it touch the recorder. You can hear some extraneous sounds (don't know what they are) but those clearly have nothing to do with the siren-like sound I'm talking about. You can hear the ~570 cycle tone, and you can hear the variability, which is not noticeable in pitch but in intensity. That could be because of environmental factors or maybe whatever's making the noise varies in sound intensity. I zipped up the WAV file and just posted it at Bayfiles:

http://bayfiles.com/file/4x6h/PfIAjb/Neighbor_Noise.zip

Does anyone have a take on this or some way of analyzing it?

 

[Rubycon]

I have had a chance to d/l and listen to it.
I do hear a lot of things, the acoustic noise floor is quite high. The train whistle is probably the loudest. I hear a heavy door (fridge) being closed heavily. Near the beginning there is a whine and a motor spinning down. Sounds like an appliance or tool utilizing a common universal motor.

There is another noise too throughout the clip but it's quite low in the recording. I have not analyzed or processed this, just gave it a listen on my interface (MOTU 896HD MkII) and UE10 pro IEMs.