Profile cover photo
Profile photo
Daira Hopwood
154 followers
154 followers
About
Daira's posts

Post has shared content
Summary: one way to adjust Debian Linux audio output volume by frequency to compensate for differential hearing loss across the spectrum, which is better than simply cranking up audio output volume.

So, I happen to be hearing impaired; one of the problematic things about hearing impairments is that hearing loss is not uniform across frequencies - for example, as people get older they tend to lose more of the higher frequencies ( https://en.wikipedia.org/wiki/Presbycusis ) which is why 'teenager repellents' work since they whine at a pitch too high for hearing-damaged post-teenagers to hear.

This has the practical consequence that to fix hearing loss, it's not enough to just 'turn the volume up to 11', since in order to bring the worst frequencies up to par you will simultaneously overcompensate & make the other frequencies far too loud. Indiscriminate amplification is better than nothing and so of course people used analogue hearing aids, but still imperfect. Modern hearing aids are digital and programmable, and can vary amplification by frequency based on one's audiogram ( https://en.wikipedia.org/wiki/Audiogram ) results showing one's personal loss curve (an example in http://auditoryneuroscience.com/?q=acoustics/clinical_audiograms ).

Mine are adjusted and while I dislike some of the downsides of modern digital hearing aids (a 1-2 second boot-up, compared to the instant-on of analogues; shorter battery life), adjusted ranges are definitely better.

I much prefer to listen to music on my headphones in order to avoid bothering other people, hearing background noise, using up batteries (see above about battery life), and so on. But dialing up the volume to compensate for hearing loss puts me right back where I started with my analogue hearing aids! It's good, but it could be better.

How? I've never seen any default audio interface on Windows or Linux include per-frequency volume adjustment. You can usually change the total volume balance of the left/right channels for the headphones (in my case, I bias towards the left a bit since there's more hearing loss there), but not by frequency. I didn't know where to go for such an 'equalizer'. (Amusing term in this context.)

I've put up with this for years but last night went looking for a Linux solution. I wandered through an awful lot of dead ends and terrifying looks at the bizarre innards of Linux audio over the last 3 decades (an abandoned Pulseaudio mixer, LADSPA, LX2, Audacity, alsamixer, alsamixer-gui, fil-plugins, swh-plugins, libasound2-plugin-equal, veromix...), but finally I think I found a solution:

a new Pulseaudio equalizer named 'qpaeq' which unaccountably seems to not be packaged by Debian (‽), but which following the guide http://mizonapc.wordpress.com/2014/01/31/install-pulseaudio-with-system-wide-equalizer-support-in-ubuntu/ can be installed roughly like this:

    sudo apt-get install python-dbus python-qt4 python-qt4-dbus pulseaudio-utils
    wget http://cgit.freedesktop.org/pulseaudio/pulseaudio/plain/src/utils/qpaeq -O /tmp/qpaeq; sudo install /tmp/qpaeq /usr/local/bin/
    pulseaudio -k; pulseaudio & pactl load-module module-equalizer-sink; pactl load-module module-dbus-protocol
    sudoedit /etc/pulse/default.pa

then edit into that file:

    ### Load the integrated pulseaudio equalizer and dbus modules
    load-module module-equalizer-sink
    load-module module-dbus-protocol

(Why not edit `~/.pulse/default.pa`? Apparently the Pulseaudio daemon will read either the system default.pa xor the user's default.pa, and never both, so I'd rather re-edit the global file everytime I reinstall Linux than have to keep a local one in sync with the arcane permutations of Pulseaudio.)

Then in the GNOME/MATE volume control, one switches the 'Output' tab to the new 'FFT...' device to enable modification, and runs 'qpaeq' to start doing the tweaking. As the guide suggests, playing music and messing with the overall volume helps confirm that it's all set up correctly.

Finally, one can start compensating for the hearing loss curve. qpaeq and my audiogram aren't on the same scale (the equalizer runs to much higher frequencies than the audiogram, which cuts off at 8khz) and bucket things differently, but that's nothing a bunch of tweaking and back-and-forthing won't fix.

The tweaks made, the state gets saved to ~/.pulse/equalizer-state.tdb, where hopefully it then is persistent and affects audio output for as long as the FFT output device is chosen.

And voila: hearing loss compensation in 10 easy steps!

(How well does it work? It's a bit soon to tell since it's relatively subtle even sitting in an audiologist's office tweaking the settings, but music seems less tiring and distracting with both the left-right tweaks and the frequency tweaks turned on.)

#hearingloss #hearingaids #equalizer #debian #mate  
Photo

Post has shared content
> “It’s DELIBERATE,” Vanderbeken asserted in his presentation.
> [...]
> Once the backdoor is switched back on, it listens for TCP/IP traffic just
> as the original firmware did, giving “root shell” access

Post has shared content
The Myth of Concern as a Limited Resource

On Monday, I posted about International Transgender Day of Visibility. Almost immediately, someone responded to the post, asking about the "more important issues out there" that people supporting this cause were obviously ignoring, such as "global warming, child abuse, animal cruelty, famine, etc.," because they were so busy worrying about this one, single thing. 

Anyone who's ever written about transgender rights, gay rights, sex workers rights and even feminism has encountered this silencing tactic. This derail is so common, it's one of the better known logical fallacies. Usually, such comments are ignored -- a fine response considering their worth -- but I want to take a moment to address this issue just the same.

Sometimes, when something happens that impacts me but I don't have the emotional bandwidth to deal with it, I joke that I'm "all out of fucks." Occasionally, I even do this to the tune of the pop ballad "All Out of Love" by Air Supply. And I'm not the only one who describes concern in terms of a fuck: "there goes the last fuck" renders 49,500,000 results in Google. Countless gifs have been made illustrating the many fucks given -- sometimes in flight, sometimes in a glass, and always in association with scarcity. We either don't want to give a fuck, or we have no more fucks left to give. 

This isn't actually descriptive of how concern works. Concern isn't a limited resource. There is no allotment of fucks we all get at birth that we need to ration, lest we run out in our thirties. When we lobby behind a cause, we're not giving up our fucks, never to care about anything again. And, certainly, if we lobby publicly, we're not attempting to get everyone to give us their fucks so that they can't worry about anything else ever again. 

Actually, once you start thinking critically about human rights, or the system, or conservation, it's a lot more likely that you will pick up on other causes worth supporting. Looking at the world this way isn't limiting -- it's expansive. 

I got into sex workers' rights through working to fight labor injustice. Sex workers' rights took me to the realities of poverty, homelessness, police brutality, legal overreaching, a broken welfare system, and more humanitarian causes worth supporting, though not related to sex work. Simultaneously, concerns over lack of sexual education took me to freedom of speech, privacy, and scientific literacy, which in turn took me to global warming, pesticides, and animal welfare, among other issues. These are only a handful of the many things I care and worry about. While it's true that we only have so much time, posts are not the only way that people signal support for change. A sex blog will only cover a handful of the issues I care about, but there are a number of ways to participate in other causes -- including donations, logistics planning, and volunteering.

Supporting a cause that has at its focus the improvement of the world is something to be applauded. Our contributions might not be great, but it all starts with that moment we say, "you know what? This isn't right." The direction that we take this initial concern might not crystallize immediately, the places it might take us might not be immediately obvious, but it all starts when someone stops and realizes that the way things are could be better. 

That's why these posts and discussions matter. That's why people who seek to derail conversations about change by pointing out that there are "bigger problems" out there aren't just unhelpful, but serious barriers to effecting any change at all -- even change regarding the issues that they actually care about. 
Photo

Post has shared content

Post has shared content

Post has shared content
Classic!! “Those who don't know history are doomed to repeat it.”

AOL 1996 vs. Windows 2012
Photo

Post has shared content

Post has shared content

Post has attachment
Me and Douglas Hofstadter (swoon) after the awesome final performance at Strange Loop
Wait while more posts are being loaded