Noise
noise

Noise pollution can have a harmful impact on both wildlife and human health. There are several notable community science projects that have focused on noise monitoring, some that use phone applications and others that use noise meters. _Lead image from NoiseTube_ ## Noise monitoring resources and projects: ### Apps Noise can by monitored by apps downloaded to your phone. Here's a [Blog post on Apps for noise mapping](http://www.opensourcesoundscapes.org/2016/08/28/a-tentative-state-of-the-art-of-applications-for-crowdsourced-noise-sound-maps/) by Antonella Radicchi. Here are some App options: - [Softhook.com](http://www.softhook.com/heathrow/technology-involved/) by Christian Nold: a DIY noise monitoring that he’s deploying around Heathrow - [Citi-Sense](http://www.citi-sense.cn/download): app for evaluating soundscapes - by Chunming Li, from the Chinese Academy of Science - [NoiseTube](http://www.noisetube.net): one of the very first apps that was developed _Note from Muki Haklay: There are issues with the calibration of phones with apps, which was an issue in some of the work that we’ve done few years ago, so I would also think that you can use class I noise meters._ ### Noise Meters - [Class I noise meters](https://www.maplin.co.uk/p/digital-sound-level-meter-n05cc) (they’re not super expensive – about £50 ) - [Sound Around Town](http://soundaroundtown.org/) adapted commercial recording units (Roland-05) and developed calibration devices so that participants in the project can borrow the equipment from local libraries and deploy in their backyards according to a specific protocol. The data will improve the NPS national soundscape maps (which need refinement but are already useful for studies of noise as an EJ issue (e.g., [this new study](https://ehp.niehs.nih.gov/ehp898/?utm_source=rss&utm_medium=rss&utm_campaign=ehp898)). ## Questions [questions:noise] ## Notes [notes:noise!question:noise] ## Activities [activities:noise] ...


Author Comment Last activity Moderation
viechdokter "@warren: I just had a look at an old spectrum CSV file of yours (3 years ago): https://spectralworkbench.org/spectrums/481 There it was unscaled ..." | Read more » about 6 years ago
warren "I went ahead and created a specific issue for native 8-bit storage: https://github.com/publiclab/spectral-workbench.js/issues/18 As well as outlin..." | Read more » about 6 years ago
viechdokter "Talking about hung-up scripts, it often is a pain in the neck to login to SBW. "Do you trust this site with your identity?" "Yes" "You must login t..." | Read more » about 6 years ago
stoft "It's ok to have a 'scaled' data file -- but ONLY if that file is clearly identified as such ... like /SpectrumData-SCALED_20160420.csv or /Spectru..." | Read more » about 6 years ago
warren "Hi, all -- 2.55 is definitely related to the 0-255 value. The code that generates the CSV is here: https://github.com/publiclab/spectral-workbench..." | Read more » about 6 years ago
viechdokter "I could re-scale but ... when everybody here gets the same minimum 2.55 increments here and you want reproducible spectral data then everyone shoul..." | Read more » about 6 years ago
stoft "Hmmm, well the RAW data should have the same scale units which would be unsigned 8-bit integer from 000 to 255 -- so the Y axis should show noise h..." | Read more » about 6 years ago
viechdokter "I took the data from the CSV files that Spectral Workbench provides with my spectra. I had a look at one of dhaffners spectrum CSV files and see th..." | Read more » about 6 years ago
stoft "Well, except there's still a problem with the plot. The smallest increment looks to be '4 steps' per scale units of '10'. Either there was some mul..." | Read more » about 6 years ago
viechdokter "Okay, here I combined the 4 channel max/min-difference curves in one diagram so they have the same vertical scale now: And here the combined dat..." | Read more » about 6 years ago
stoft "Or, they are all 'bad' (noisy) to some degree ;-) The sharpness of the peak is still mostly a factor of slit, mechanical rigidity, being light-tigh..." | Read more » about 6 years ago
viechdokter "Looks like at least there are no "bad" pixels as they all show about the same amount of noise. The time averaging seems to achieve a very sharp-pe..." | Read more » about 6 years ago
viechdokter "Talking about bits and quantization: I also noticed that certain values (2.55 and multiples thereof like 5.1, 7.65 ...) appear in every spectrum's ..." | Read more » about 6 years ago
stoft "Yes, it's called quantization; the camera only has 8-bits and the scale of the two plots is likely about 3-5x different. Take a look at the 'red' p..." | Read more » about 6 years ago
warren "Hmm, very interesting -- without vertical scale its hard to say though - I believe the "plateaus" on the "average curve" are artifacts of the preci..." | Read more » about 6 years ago
viechdokter "@warren:They would be low-noise green if you average them. ;-) @stoft: BTW, I noticed that curves that were averaged over two or more channels l..." | Read more » about 6 years ago
warren "Would he be low-noise green? :-) I'd also love to see them plotted on the same graph, maybe with the graph lines themselves in appropriate colors...." | Read more » about 6 years ago
viechdokter "Yeah, I think I could do it. Hmh, I must admit that I only pretty recently started to use Excel-like programs at all. To be honest, your research n..." | Read more » about 6 years ago
stoft "I believe both Excel and Quattro Pro provide for multiple plots. I suspect your's may as well -- in Quattro it's under the specialty xy plotting. I..." | Read more » about 6 years ago
viechdokter "Yes, you are right. I, too, like comparable curves better. I used LibreOffice, a kind of public domain "Excel". It plots diagrams automatically and..." | Read more » about 6 years ago
stoft "Not to worry, I too find bits to revise after I publish; what counts is fixing the details as they appear. One thought on visualization. When I do ..." | Read more » about 6 years ago
viechdokter "@stoft : sorry I had to revise the research note as there was a big mistake in the red curve. I exchanged it with the new revised red curve and now..." | Read more » about 6 years ago
stoft "Right. That's the Bayer filter pattern which sits in front of the imager chip and gives double the signal sensitivity for Green -- a simulation of ..." | Read more » about 6 years ago
viechdokter "@stoft : RGGB like in this picture? " | Read more » about 6 years ago