Pronunciation: [ɡˈɪlbə͡ʊ] (IPA)
Correct spelling for the English word "gilbeau" is [ɡˈɪlbə͡ʊ], [ɡˈɪlbəʊ], [ɡ_ˈɪ_l_b_əʊ] (IPA phonetic alphabet).