How do you reassure a scared 1yo?

DS has developed a fear of the garbage truck. The noise freaks him out big time. As soon as he hears it he starts whimpering (before I can even hear anything!) then reaches out for me, goes all stiff and cries/screams. The only thing I can do is hold him so so tight and repeat ,'It's OK' until it goes away (5-10 mins as we have some cul-de-sacs nearby and you can still hear it). Then it comes back the other way and we start over again! If we can, we go outside and watch it go past (both ways) and he's fine while he can see it, but sometimes we don't get out in time. In that case, it can take 15 or so minutes for him to calm down again. Today we walked to the end of the street so we could see it because he just wouldn't relax or eat his morning tea.
What can I do or say to reassure him? I don't want him to develop a fear of garbage trucks! And how long will this 'phase' last, assuming it's a phase? TIA

Can you distract him with something? Make it so the noise isn't even worthy of listening to let alone being scared of?

What about a garbage truck toy? Book of trucks? Work on desensitizing him to it more? And making lots of truck sounds, talking about noisy trucks etc? I can only think as he gets older and puts the noise with the truck before he actually sees it he might not be so scared eventually? When he gets scared at the first sound of it, maybe stay really positive and light and grab the truck toy/book etc and of course comfort him but match the noise with the object/distraction itms? Not really sure if any of this will work, just throwing round ideas :)

I know what you mean about hearing it though, we have a truck that lives next door and DD hears it way before any of us and goes running to the door shouting something that I'm sure means 'truck' in baby talk.

Helle - even his fave distraction, food, didn't work this morning! I've tried singing, pulling faces, looking at the birds, toys etc but will keep trying more stuff.

Human Bean - That's the theory I'm trying. Every time we see a truck (irl or pic), I tell him it's like the rubbish truck and make a big noise, just so he gets used to hearing the words rubbish truck. So when he hears the rubbish truck I can tell him what it is and hopefully he'll recognise the words and find them reassuring iykwim?

Could it be that there is something in the noise that is irritating him, the frequency of some of the noise it makes that is painful for him? It might not be the truck itself.

Hope this helps