A boxed set of Lister's Sounds, designed by Lord Lister.
They have a characteristic "lollipop" handle and olive tip.
The rounded olive tip was safer to probe urethral strictures being less likely to cause a false passage.
This set is incomplete but, in the bottom slot, is a "stone searcher".
The stone searcher has a completely different curve.
This is a true "sound". What we tend to call sounds are usually urethral probes or dilators.