wearwell wrote:What evidence? Have there been trials of hearing and non hearing cyclist behaviour?
Yes, there have (although the most prominent study is of very questionable relevance) and there are also some other data which are pertinent. If you follow the links I've posted you'll find it.
wearwell wrote:In the absence of science "common sense" has to rule - and it's certainly sensible to take notice of the sound of an HGV approaching from behind or otherwise out of sight.
"Common sense" is absolutely fine for individual decisions, but—not least because it's quite often flawed or even flat wrong—it's a very poor basis for population policy decisions.
wearwell wrote:I often cycle without my hearing aids because of wind or traffic noise. This entails very different behaviour - mainly a lot of cautious extra vigilance - looking over one's shoulder etc.
So you're saying that when you are deprived of the sense of sound you consciously rely more on the sense of sight…? Given that sight is far more reliable a means of assessing the immediate road environment, wouldn't "common sense" potentially imply that even though you may
feel ill at ease, your compensation means you may actually be
safer in this case?
wearwell wrote:I didn't say that impaired hearing was a factor - I know nothing about this case.
No, what you were saying was that you disagreed with the evidence that music can improve someone's ability to focus on a cognitive task, on the basis that their ability to hear may be compromised. My point is that these are different things.
wearwell wrote:What I am saying is that in general, hearing is undoubtedly a factor in road safety, especially for a cyclist. In this case she was at risk wearing earphones, whether or not they were part of the cause. Actually it seems so obvious it surely shouldn't be necessary to argue it at all.
Things that "seem obvious" often most necessitate discussion, because things that seem obvious but aren't true cause a lot of problems. All your statement says is that you don't really care what happened in this situation, you're going to use it as confirmation bias that listening to music
must increase risk. You're just making assumptions.
I should say, in case it wasn't perfectly clear already, that I'm not saying that everyone should start using headphones. I'm not a headphone user. And I'm not even saying that there's no negative effect from using them. What I'm saying is that there's no evidence of a negative effect, and that simply repeating "it must be true, it's common sense" is not a valid argument outside of a Ukip party conference.