Police cars: crazy new sound effects

[treehugger]

I was cycling home from work this afternoon and was overtaken by a police car, which not only had a siren and blue lights but an additional, overlying crazy sound track. I actually thought it was some young hooligans with a novelty gas-powered horn system. We live on Barry road and I dread these crazy cars tearing up and down at all hours. Is this extra layer of noise really needed?

[muffins78]

I heard it too, it was very bizarre

[uncleglen]

Maybe they had their Iron Maiden CD playing full blast at the same time!

[Burbage]

uncleglen Wrote:

-------------------------------------------------------

> Maybe they had their Iron Maiden CD playing full

> blast at the same time!

Not quite, but close.

I think they're designed to solve two problems.

The first problem is that those obliviously sitting in their nasty boxes with Iron Maiden, or Woman's Hour, turned up to 11 can't, or prefer not to, hear the sirens.

The second is that just blatting out a traditional siren noise is that, from some angles, it's difficult to tell where it's coming from and, in some circumstances, it'll become inaudible. (If you ever studied 'waves' in Science, you'll know that this happens, and that there's no interesting way of explaining it). Even if the Met wasn't yet bored of running people over, the mayor was getting tired of the headlines.

To get round these problems, they have two main tricks. The first is changing the frequency of the siren, swooping it up and down, which makes it, theoretically, more audible from different directions. The second is to use s smear of frequencies (that's the grinding noise) that can cut through at least through the mellifluous clamour of Iron Maiden.

Because they can't really have everything going on at once without deafening pedestrians and cyclists (not, I suspect, that Plod cares very much, but the manufacturers have lawyers), the sirens are now designed to do the different things in sequence, so they'll switch, sometimes fairly quickly, between a bit of siren, a bit of swoopy noise and the grindery stuff. Unfortunately, this isn't just funky but very effective, so we'll just have to get used to it.

[minder]

We get these loud and crazy sound effects every Saturday and Sunday morning around 6am when there isn't any traffic! Shame they're not around during the day/afternoon when there's so many burglaries taking place in the area.

[nutty]

They are seriously late to the game too. This was developed back when I was at Uni...

http://reporter.leeds.ac.uk/443/news.htm

[PeckhamRose]

I was caught in a stuck queue in the Blackwall Tunnel on Saturday and a police bike zoomed down and as it caught up with us bikers near the exit, the sound of it - echoing around and around the tunnel - was truly deafening even with a helmet on. and the lights bouncing around made one suddenly feel like being in the middle of a live video game. Temptation to race the police biker out the other side of the Tunnel was, thankfully, suppressed.