I've got a product similar to these and they're great. You can have a normal conversation and it didn't take me long to realize their eavesdropping potential. My Surface headphones also have a feature that more or less acts as a hearing aid.
Some years ago there was a set of headphones sold for hunting (amplifying sounds of animals and reducing gunshot noise) that were very popular among the hearing-impaired community as a cheaper alternative to hearing aids.
If all you need is to amplify everything, they work fine.