Well what an excellent way to marry your love for music and audio with your love of politics! By the way, what other interesting things did these German audio scientist girls have to say to you?
On Tue, Feb 9, 2021, 3:06 PM Andy Farnell <[email protected]> wrote: > On Tue, Feb 09, 2021 at 11:46:25AM +0100, Sound of L.A. Music and Audio > wrote: > > Thanks Andy for this post! > > > > One issue around that is hearing systems. Regarding localization we have > > the unhappy effect that noise in the streets confuses also handicapped > > persons since the electronic hearing systems are oversteared by a) > > general loudness but b) also by individual sound sources which they try > > to eliminate. > > Saturation of machine listening and hearing aid systems isn't something > I thought of. Most AGC circuits would struggle to adapt to that kind of > dynamic range shift. > > I hope that other list members don't find this deviation from strictly > music related DSP unwelcome. Probably there are creative solutions > lurking in our midst and the thread can be adapted for Pierre's > students or others. > > As I recounted to Brian, the talk I was did about sirens came from > experience of an earlier project, sitting on an expert panel at UCP > Porto. It was about electric vehicle (eV) sounds. We had motor > industry engineers, residents associations and disabilities groups to > figure out some parameters for the warning sounds. Like sirens, it is > also a fascinating problem. > > At speeds below about 25mph the noise from tyre "squirm" (which is > actually the dominant sound from modern vehicles) does not > happen. Above 10mph a car can be lethal. So from 10mph to 25mph, the > main range of speeds for manoeuvring in city centres, eV's make no > sound but can kill. > > So here we have many differing spheres of interest and no one ideal > technical solution. > > 1) The city planners and residents want no sounds. They say, "Why not > take the opportunity to have quiet cities and change the way we use > roads?" > > 2) The disabilities and safety groups (particularly the blind) want > the maximum noise from eVs - basically annoying beepers on all cars. > > 3) Car manufacturer's want to use the sound for branding. They want > intellectual property on their signature eV engine sounds! They also > continue to tout acoustic isolation (low cockpit ingress) as a comfort > feature. > > 4) Drivers say they use the audio-haptic feedback to help them > drive. Research says they only _think_ that, and in fact there are no > differences in the efficiency or effectiveness of driving with or > without sounds. Besides, there is no reason that cockpit and exterior > (emission) sounds need be the same if electronically generated. > > Techno-solutionists want eVs to emit directional Bluetooth beacons > that cause people's smart-phones to vibrate. Or to encode data into > the eV sounds that can activate warnings in the path of travel (a > possibly cool idea IMHO if you can get around Doppler messing with > your encoding frame). > > The best solution I heard came from two German girls, students who > designed a mechanical air siren with a spinner that starts making a > low noise at 10mph and a centripetal lock that stops it at 25mph, with > pitch and amplitude proportional to velocity, and a manufacture cost > of a few bucks. It wasn't what the technologists wanted to hear about, > but in my opinion was pure lo-tech elegance. > > So, as you'd imagine the problem of sirens is equally complex. > Locating the source of a fast moving emergency vehicle (EV) is just > one problem. Some sounds disorient and panic drivers. Where it's the > law that you must move aside from EVs, sirens get used less if short > bursts and lights are used (Sweden/Denmark). Dash-cam footage shows > the effects of long and loud wail sirens are devastating - drivers > swerving into cycle lanes, getting flustered and actually blocking the > path of EVs! > > Many jurisdictions place time limits (duration and hour of day) on > sirens. In the UK, EV drivers rarely observe these. 23h00, is the > cutoff, but I regularly hear sustained sirens after midnight. Who > would complain? Nobody wants to be seen "enforcing" rules on people > saving lives. > > I've had many students in the past do street level measurements. They > all come out as _very_ illegal. But there are legal exceptions to > sirens. One clever get-out is that they are treated and measured as > impulsive rather than continuous, which changes the measurements. > > None of this can be separated from the wider political context. In the > UK governments have slashed civic and health-care funding, reducing > the number of police, fire and ambulance stations. When I did research > in 2012 I think the average distance travelled had doubled since 1980 > to about 10 miles, making the journey time impossible to hit targets. > EV drivers are squashed between multiple forces of unreason. Response > time targets get shorter, roads get busier, available EV resources get > less and pressure from insurance companies is ramped up. > > At one time in the UK, EV drivers had 'Crown immunity', > indemnification against liability from an accident. That was > axed. Although Road traffic Article 99 says that EV drivers may > exercise discretion, in practice they over-use sirens out of fear > leading to deprofessionalisation of the job. > > These are just a few of things I discovered in my cursory research of > why our cities are so bloody awful to live in. No doubt it is more > complex and my facts are out of date now. One of the most tragic > ironies was that most medical emergencies requiring fast response are > strokes and heart attacks, the very cardio-vascular traumas most > linked to noise pollution - which is why I titled the talk "Iatrogenic > Sound". > > All that said, I think there are enormous opportunities for sound > designers, DSP engineers, psychologists and acousticians to improve > the situation. > > best, > Andy >
