Wireless Bells, or How I Learned To Bleed From The Ears

[Jashank]

I'm in love with the concept of wireless bell triggers for buses. It's a great idea.

If you look in the side of the new egg-shaped buttons in the CB80s, you will see a small metal whistle, which is a part of the button system. When you press the button, it pushes air out through the whistle. Perfectly sound (excuse the pun).

What hasn't been taken into account by the designers of these devices is that humans can hear up to 22 kHz. These whistles are at ~18.5 kHz and are unpleasantly loud, especially for younger travellers. At these frequencies, one good description of the sensation is having one's ear forcibly removed. For instance, as a school student, I often use school buses in Sydney, and at one stage, V's new CB80, MO2373, was on a school run, where the driver was unaware of the students deliberately pressing the buttons in an attempt to cause discomfort to others.

I sent mail to NSW STA and got a fairly generic letter back, the gist of which was, "All of State Transit's buses are in line with the Australian Design Rules Specifications, a requirement under the bus contracts. These standards are suited to the average Australian and are complied with by the Australian Bus Manufacturers as part of contractual requirements."

So what, are young people no longer average Australians? It would seem so.

This issue came to a head when I was on Forest's MO5441 yesterday and had a 'friend' deliberately (and gleefully ) press the button repeatedly. After this, I made calls to Forest (who essentially said they couldn't do anything) and left a message with Custom Coaches.

A gentleman (missed his name) from Custom Coaches called me back this morning, and I had a discussion with him about the bell frequency. Apparently I'm the only person who has encountered this obvious flaw with these devices in the entire world -- these devices are deployed in Europe and there haven't been any issues with them there. As I pointed out, using freely available audio analysis software and a quick perusal of Wikipedia (cf. http://en.wikipedia.org/wiki/Hearing_range#Humans) would immediately lead one to find that 18 kHz (and, indeed, anything less than about 21-22 kHz) is audible to humans. The guy from Custom Coaches advised that the devices are manufactured in Italy and France, and that they would attempt to get in contact with the manufacturers and get back to me at some point in the near future.

Forum readers: have you experienced discomfort from these bells?

~j

[DiAmOnD T]

Yes, I find them annoying when constantly pressed (had the demo bus when it was new) but as you have been told it is legal via an Australian Standard. There is not a thing that the end user (Custom) has to account for as they are providing buses built to a standard set of rules for operators.

If you feel it is that bad you should bring it up with the manufacturer and/or the governing bodies for noise testing.

[paulbrown3]

I traveled on red bus service cb80 #95 and found that the next stop buzzer was not really loud considering the buzzer is up near the front of the bus, compare this to the rest of the noise someone encounters on a bus, both human and Mechanical (bus rattles)

[Jashank]

I traveled on red bus service cb80 #95 and found that the next stop buzzer was not really loud considering the buzzer is up near the front of the bus, compare this to the rest of the noise someone encounters on a bus, both human and Mechanical (bus rattles)

It's not the next stop buzzer -- it's a whistle physically built into the button. I find this even more excruciating than, say, the sound of upset infants or loud mobile communicators.

~j