[fiddlosopher]

All the vowels in Navajo can have a hook under them (indicated nasal tone) and an acute accent above them (indicating higher pitch). The "ł" is not pronounced as in Polish. It is a voiceless alveolar lateral fricative. Try to pronounce l and s at the same time and you'll be in the right ball park. Navajo vowels also come in long and short duration; a doubled vowel means long. (I know all of this because I designed a font for Navajo in the early 90s, while working on the Navajo reservation. I don't know if it ever got much use, though I once saw a children's book typeset in it. Most of my friends who spoke Navajo did not read the language, probably because there wasn't enough written in Navajo to make it worth while for those who had learned to speak it growing up to learn to read it as well.)

Edit: I didn't comment on ń. According to "An Introduction to the Sound System of Navajo," by Ken Hale and Lorraine Honie (MIT unpublished ms), "the sequences /ní/ and /ni/, when occurring before consonants, are often pronounced without the vowel; instead, the nasal becomes syllabic and carries the tone originally carried by the vowel. When this happens, the tone mark is transferred to the nasal -- thus /ní/ is written [ń]; in the case of low-toned /ni/, a special tone mark [`] is used for the syllabic nasal..." I was excited to find all of this unpublished material from the late Ken Hale here: http://www.swarthmore.edu/SocSci/tfernal1/nla/halearch/halea...