Sounds in the urban environment that aren't intended to give information, but do anyway

Today I went to another one of the Interactional Sound And Music (ISAM) reading group / meetings where I work. I don't work in the area and don't have any direct link with that type of research but I'm ridiculously fond of sound-related stuff and the group has made me feel very welcome. Their stuff fascinates me.

One of the things we talked about today was the type of sounds that people meet in their everyday urban environment - cars honking, train doors beeping etc and how some of these might be intended to convey some information (help, get out of the way, pay attention) and whether or not that works particularly well.

It appears that quite a lot of these sounds don't quite hit their mark - people might not understand what the sound is meant to indicate, the sound is unpleasant and avoided or the sound competes with other sounds (including headphones) etc.

People were talking about how to make the information a bit richer - for example microwaves beep when the cooking time has elapsed but the beeps don't tell you much about the state of the food (is it cooked? Presumably some information about the combined time it's cooked for plus temperature information in the oven could be used). I'm someone who's not a fan of microwave beeps so I hope any research-based developments here keep the beeps short and sweet.

I've thought up some of the sounds I'm aware of in London (and a little bit beyond) but wondered what other sounds you're aware of in your local area and what they're trying to tell you. I suppose it's meant to be just designed sounds, so the sound shoes make when someone's walking on different surfaces might indicate if they're walking on grass, tarmac or cobbles (and also indicate the type of footwear that's being worn) but the shoe designer probably wasn't thinking about the sonic properties of either shoe or environment.

Other non-designed sounds in our environment that can give info might be the sound an engine makes - people more familiar with them than me might know from the engine's sound if all is well or not.

It might be quite fun to have a quiz of sounds that would be familiar to a British audience. There was a crowdsourced project a few years ago collecting urban soundscapes and you could easily tell if it was London or New York for example.

Although not really related to my work on the CHI+MED project (about making medical devices safer) some bits of it do remind me of the concept of resilience strategies. These are unofficial practices that people adopt to prevent some problem or annoyance from happening - eg leaving something by the door tonight so that you don't forget to take it tomorrow morning. An example might be observing a particular sound and noticing that it tells you different information if the sound is different (eg the engine example above).

Here is my slightly random taxonomy of urban sounds that will probably have bits moved around and new sections put in, etc.

Sounds that are intended to give information, and mostly do

• Alerts or warnings
• 5 fake sounds designed to help humans Humans Invent blog (20 June 2011) - covers the car door 'clunk', the 'vroom' noise of electric enginers (which are otherwise almost silent), extra sounds added in to a mix, such as crowd sounds fed through stadium speakers, 'comfort noise' to radios broadcasting a minute's silence and a debate on whether or not the whirr of a cashpoint accurately reflects any real-time money-counting procedure.
• Pings and buzzers on buses and trains, might also include spoken instructions over tannoys and the GPS bus location info ("341... to.... Chancery Lane.... this is... Angel"), as well as the ping to let people know that the bus is going to stop at the next stop (it also tells people that there's no need to press the buzzer temselves)
• The alarm sound that Tower Bridge makes when it's about to open or close
• The sound that larger vehicles make when reversing - this can be sonic (beeps) but some also have verbal warning ("whoop whoop whoop, this vehicle is reversing")
• The alarm call that is fitted to all London buses that makes a high-pitched sound and then says "this vehicle is under attack, dial 999" - these ask passersby to take action
• Emergency and police vehicles driven under blue light conditions with sirens on - these say get out of the way
• Office telephones that distinguish between internal and external calls
• The 'ping' that train doors make to indicate that it is now possible to open them (also matched with a flashing light on the button used to open them), similarly elevators often ping on opening and give verbal instructions 'the lift is on its way' or 'floor 3, ladies coats and handbags'. Not sure that this really counts as urban but aircraft also have a 'you may now unbuckle your seatbelt' that has an accompanying ping. It's so recognisable I can hear it in my head.
• Oyster reader units (the bits you touch in / out) make a single pitched beep when an Oyster card is successfully read and there's enough money on it. I don't have an Oyster card but I do have a card with a chip in it that the readers don't recognise. This results in a lower-pitched 'annoyed tone' of two beeps (the error message is '77'). This YouTube video explains how to use Oyster card and also has examples of the two different beeps.
  
  This is more for the next section but in googling Oyster card beeps to see if there was much info about the different kinds and what they mean I discovered something I'd spotted but forgotten - a child's card also makes multiple (assume 2) beeps. Someone's noticed it though and created a Facebook page with the title "If her Oyster card beeps more than once she's too young for you bro". Lovely ;)
  
• Air raid siren - very evocative. Most people living in Britain would recognise this even if they weren't alive when they were used to indicate danger - we've all seen the films and understand their meaning. Nowadays we might not know what to do if we hear one in real life - is it a surprise fleet of enemy aircraft or just testing the flood warning?
  
• Communication
• Horn-honking from lorry drivers, sometimes used to show solidarity when a lot of lorry drivers are campaigning or annoyed about something, obviously cars use them to say 'get out of the way' and the Thames Clipper ferry captains use them to acknowledge other vessels. Cyclists also have bells or horns.
• That three note rising tone that indicates to on-board train staff that it's time for them to go and collect rubbish or distribute beverages - I don't know which trains it's in use on but when I mentioned it today a few other people were familiar with it. I only found out what it was when I happened to be sitting in part of a train that had the on-board staff sitting behind me and every time the sound went off they'd leap up to go and do stuff. Previously I'd not spotted the causality because I was sitting somewhere else in the train and so the sound wasn't temporally linked to any obvious event.
• bing-bing-bing, three tone dropping in pitch, of old-fashioned public address systems to alert people that a message is about to begin
• The Audio Captcha which plays a scrambled message and asks you to pick out words that you can hear (it sounds rather spooky) [recording]

Sounds that are not intended to give information, but do

• Ridiculous ring tones broadcast to everyone in the vicinity that their owner is a bit of an idiot and this might well be combined with a loud one-sided conversation which further confirms it. But if people use key-clicks with a dual-tone multi-frequency (such as you get on most touch tone type phones) then it would be possible for someone with a good pitch awareness to work out what numbers are being pressed, and possibly surmise something about the letters used in a text. The video below shows a two year old child doing this with ease.
  
  
  
  
• The 50 or 60Hz mostly inaudible hum from mains electricity has been used forensically to pin down the time, from fluctuations in the frequency, that an audio recording was made "Any digital recording made anywhere near an electrical power source, be it plug socket, light or pylon, will pick up this noise and it will be embedded throughout the audio." More info at http://www.bbc.co.uk/news/science-environment-20629671 - not a designed sound, but nicely exploited.
• Alice Bell's post on How the refrigerator got its hum charts the history of competing refrigeration technology but also gives an example of a friend of hers who noticed that the sounds her fridge made gave an indication of when she needed to put another 50p in the meter. I've just added, to my Soundnoticeboard blog, a related example of an Electrolux freezer manual that includes cartoon images of the freezer and words indicating the sounds it should be making under normal operation. I've never seen anything like it!
• It's pretty easy to tell the number of carriages making up a train solely from the sound made as the wheel units pass the points - the traim below, with 4 carriages would sound like this:
  

  [da-dum.....da-dum]-[da-dum.....da-dum]-[da-dum.....da-dum]-[da-dum.....da-dum] 
   o-o           o-o   o-o           o-o   o-o           o-o   o-o           o-o

  - although this isn't really a designed sound. And now I'm wondering if the 'da-dum' isn't actually the last wheel of the carriage followed by the first wheel of the next carriage, ie not da-dum, da-dum but just da-dum. More research needed.
• The sound that rails make when a train or tube is approaching, this sound often appears before the train is visible where there's a curve, there are other sounds that the train itself makes but the flexing of the rails ahead of the train heralds its arrival // the sound that points make when they click, which indicates when another train is coming and might indicate something about its direction (I've not worked it out). Again, not a designed sound, just the sound something makes.
• It's pretty obvious when my toaster's stopped toasting ('pop') and my kettle's stopped boiling (the on-button pops to off).
• See the bit above on Oyster beeps. A child's card makes a different sound from an adult's - presumably the intention is to alert bus drivers etc that the card sound matches the apparent age of the child and not someone using the wrong ticket. But people have surmised another meaning from it. 
• Edit 16 September 2014 - our printers have been offline this morning, don't know why, thought I'd wait a bit before pointing it out. Then I could hear the sounds of the printer outside my office springing into life so this obviously communicated to me that the servers were back online.