Altitudes rhymes with:
platitudes, platitudes, aptitudes, attitudes, etudes, latitudes, longitudes, magnitudes, platitudes, aptitudes, attitudes, etudes, interludes, latitudes, longitudes, magnitudes, megafoods, multifoods', multitudes, platitudes, preludes, seafoods
Altitudes sounds like:
aeltus, ahold's, aholds, alatas, aldaco, aldis, aldous, aldus, aldus's, aldys, allied's, allots, alludes, altaic, althaus, although, althouse, altice, altos, altus, aulds