Some alphabets disregard tone entirely, especially when it does not carry a heavy functional load, as in Somali and many other languages of Africa and the Americas.
sˌʌm ˈælfəbˌɛts dˌɪsɹɪɡˈɑːɹd tˈoʊn ɛntˈaɪɚli, ɪspˈɛʃəli wɛn ɪt dʌznˌɑːt kˈæɹi ɐ hˈɛvi fˈʌŋkʃənəl lˈoʊd, æz ɪn səmˈɑːli ænd mˈɛni ˈʌðɚ lˈæŋɡwɪdʒᵻz ʌv ˈæfɹɪkə ænd ðɪ ɐmˈɛɹɪkəz.