Now that you mention it, his voice does sound different. On the rock hall of fame awards, when he sang I still havn't found what i'm looking for" it sounded different, but i just assumed it was becuase it was live, and live always sounds different when recording in studio. But most of the songs on HTDAAB are lower in range. But after sugery, your voice would prolly change, and over the years time does take effect, but he still sings wonderful. Although he is singing elevation on this tour(and there are high parts in the song)...anyone who went to previouse concerts in the past month, did his voice sound extremely different? I guess i'll know after the M.S.G show. Anyway, Bono's voice is still great, one of the things i love about it , is when ever i hear i u2 song, you can just automatically can tell it's a U2 song, because Bono has quite a unique voice! (and plus, after listening to all their songs over the years, you should be able to know every one!)