Picking up this old (and useful) thread to say that today I did some comparative testing with several custom-fit (ie moulds made by an audiologist) ear devices.

Goal is to protect my hearing on those (hopefully rare) occasions when I have to do a long stretch of motorway driving, eg to reposition the car for a drive in Yorkshire or whatever.

All these solutions let sirens etc through. They take a little getting used to -- and they remove most of the lovely Morgan engine noise which is unfortunate, but I'd pull them out once I get off the motorway. All have some wind noise with or without the side panels mounted.

1. Custom in-ear monitors from Ultimate Ears (US) - these have fabulous audiophile quality and near-complete sound isolation (I wear them on aircraft; their primary market is rock bands) but were problematic in the Morgan: wind noise striking the outside shell is very bad. Mine were attached to a small bluetooth box (Quedelix 5k) which allows some external sound to be mixed in. But the wind noise was too unpleasant, even when wearing a cloth cap with fold-down ears.

2. Musicians' earplugs from ACS (https://www.acscustom.com/uk/products/pro-series/). These have a small filter that "tunes" the sound it lets through. They were quite successful - no wind noise and a good reduction in road noise. Most importantly they cut out the high-pitched noise that makes UK motorway driving so horrible with the roof off. It think it would be possible to have a conversation wearing these but haven't tested yet.

3. Soft earplugs made for side sleepers from Ultimate Ear (nb singular - a UK company) (https://ultimateear.com/product-category/custom-sleeping-earplugs/). These are great for sleeping and produced almost the same effect as the musicians' earplugs, perhaps slightly duller sound.

4. Apple AirPods Pro 2, fitted into AirPod Gloves from Ultimate Ear (https://ultimateear.com/product/custom-apple-airpods/). Slightly strange gadget: the custom ear mould provides a little bit more sound isolation, but its primary goal is to hold the AirPods firmly into the ear -- I'm sure they would blow out in the wind without the "gloves". This was the winner for motorway driving. Apple's noise reduction is very good. Connected to an iPhone, I could hear music, podcasts, directions and speed camera warnings - and even answer the phone, a capability which was too modern for Morgan to include in my CX Plus Four. A quick click on the stalk and they can be switched into transparency mode which allows for conversation and returns some - just enough - of the outside sound -- good to do when you peel off the motorway and into a village. They do stick out a bit and perhaps a passing police office might want to have a chat -- but I don't see a problem as they reduce sound less than a conventional car would do. Somewhat clumsy to fit as you have to rotate the sleeves into your ear canal without rotating the AirPods themselves relative to the sleeves (there is a little hole which needs to match a microphone).