on-screen font sizes

[Jack Tanner]

Is there any way to change the size of the "typerwriter" font used on-screen for
ERT, program listings, and the like, and not change the size of the other
on-screen fonts? My document font is just fine, but the typewriter font size is
too big. Under Tools->Preferences->Screen Fonts, it seems like I can only change
them at the same time, not separately.