I personally prefer to use, and recommend, the AKG K240DF headphones, but be sure to get the DF ones. They are flat and are made to sound like a non-reverberating room (the big term is "anachoic chamber") plus they are open back so you can wear them a long time without ear fatigue. Your wife would be able to hear slightly but not much. The ear pads are very soft and comfortable and I use my pair all the time. They now cost about $160 at zzounds or musicians friend.
Tom
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Bigger is not always better
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Bigger is not always better