CAN YOU HEAR NOW? If you feel tormented by ambient airplane noise or your spouse's snoring in a hotel room, pity the target shooter with a rifle cocked at ear level. OK, don't, but you must admit that's an excellent venue for testing the mettle of noise-blocking earmuff devices, which are the refuge of those who can't tolerate earplug-style sound mufflers. That might get you over the hump of considering the "shooter's folding earmuffs" from Howard Leight, a topnotch defense against encroaching decibel levels wherever the threat. Two ultra-slimline, lightweight models designed for those who want maximum silence with minimum bulk are the "passive" Leightning LOF Earmuffs, which block out all noise (noise reduction rating 23 dB), and the Impact Sport Noise Canceling Electronic Earmuffs (NRR 22 dB), which has a jack for electronic devices and controls that let you have a conversation by amplifying low-level sounds (2 AA batteries and 3.5mm-plug audio cable included), while cutting out harmful levels above 82 decibels. Both models have adjustable padded headbands and thickly cushioned plastic ear cups that keep the essential tight-seal fit from being uncomfortable (perhaps not for everyone). Both have spring mechanisms that allow the muffs to fold out for use, then pop back in compactly to about 5 inches by 4 inches by 4 inches thick. Not diminutive, but we're talking major fortification.