Does hearing loss generally remain stable?

It does until it doesn’t.

All losses can change with the influence of outside factors but: generally sensorineural losses tend to remain largely stable (with slight decline over years), as do big conductive losses. Moderate mixed losses have the propensity to worsen and improve with underlying health/pathology changes.

So it comes down to what is causing the loss. If that condition has a propensity to worsen/vary your hearing then you’ll get changes. The best example (which disproves my point above about SN losses) is Menieres: this can come on in waves, attacks or just mild inclination. You’ll get sensorineural changes, tinnitus and vertigo. However, it can be reversible, occasional or persistent in nature to varying degrees of effect. It’s pretty rare, but if you get it; the degree to which it carries on is pretty difficult to predict.

So, like I said, your hearing stays stable until it doesn’t. Protect what you have from machinery/music noise and deal with it, if it changes.

Edit: SN loss at 16 is a bit left field, have you had any extra analysis done/family history?