Seeing as audio has yet to be added to the Navajo course, here is a quick guide to pronouncing Navajo:
Navajo only has 4 vowels: a, e, i, o which are pronounced like their English counterparts*, however it does everything it can with those 4 vowels.
*NOTE: the 'a' is pronounced like the 'a' in 'father' and the 'i' like the 'ee' in the word 'see'
Firstly, Navajo has nasal vowels (like in French and Portuguese). These are marked with a dash underneath the vowel: ą . In case you aren't aware, you nasalise a vowel by lowering the velum so the air flows through the nasal canal instead of the mouth.
Secondly, Navajo distinguishes between long and short vowels (like Japanese). When you see double vowels, such as in the word 'hooghan' (traditional Navajo houses), that means it is a long vowel.
Lastly, Navajo has a simple tone system, meaning vowels can be high pitched or low pitched. Only high-pitched vowels are marked, using an accent above the vowel: á . As well as a steady low-pitched and steady high-pitched tone, Navajo also has falling and rising tones, however these are only found on long vowels: àa = falling tone, aà = rising tone.
Navajo vowels can have any combination of these features. For example, the word for horse is 'łį́į́'. The vowel sound here is a long, high-pitched, nasalised 'i'.
The letter 'b' in Navajo actually makes a 'p' sound (there is no 'b' sound in Navajo), where as the 'd' makes a 't' sound. The letter 't' is found in Navajo, however it produced a 'tx' sound (the 'x' is explained further down).
'sh' and 'ch' produce the same sounds that they do in English however there are two other combinations you should be aware of: 'zh' which makes the same sound produced by the letter 's' in the word 'Asia', and 'gh' which speakers of Dutch will be familiar with as the 'Dutch g'. It is produced by preparing for a 'g' and holding the tongue in that position as the air flows out.
The letter 'x' is pronounced like the 'ch' in 'loch' or 'Bach', it is a stronger version of the 'gh' sound mentioned above.
The combination 'hw' sounds more like the aforementioned 'x' followed by a 'w', whilst the combination 'kw' sounds like 'hw' but preceded by a 'k'.
The letter 'ł' is somewhat similar to the same letter which can be found in Polish. It sounds a bit like an 'l' and a 'sh' being produced at the same time. The combination 'tł' is pronounced like the 'tl' at the end of Aztecan language Nahuatl.
Navajo, like Hindi, has aspirated consonants; these are consonants followed by a short puff of air. These are marked quite oddly in Navajo orthography. For instance 'ch' makes an aspirated 'ch sound, whereas the letter 'j' corresponds to a non-aspirated 'ch'. To tell the difference, pay close attention to the word Chechnya. The first 'ch' is aspirated, whereas the second is not. The only other consonant in Navajo which distinguishes between its aspirated and non-aspirated form is 'ts'. The aspirated form is written 'ts' whereas the non-aspirated form is written 'dz'.
Navajo also has ejectives. These are hard for English speakers to produce or pick up on, however ejectives are essentially the sounds made when beatboxing. To produce them, pronounce the consonant as you normally would, but without releasing any air (hold a piece of paper a short distance from your mouth to practice this). Ejectives in Navajo are marked with a ' after the consonant and be found after a k', ts', t', tł', ch'. (Tip: the aspirated ch' is found in the English utterance 'achew' to imitate a sneeze).
Not to be confused with ejectives is the glottal stop, which is marked identically, but only follows vowels. I like to think of it as 'catching' the vowel in your throat, however a more concrete comparison would be with the English word 'uh-oh', where the hyphen marks the glottal stop.
Lastly, the letter 'y' is usually pronounced the same as in English, however it can sometimes sound a bit closer to a 'j' sound.
'l', 'm', 'n', 's' and 'z' are pronounced just as they are in English.
I know this is a lot to take in however hopefully they will release audio soon for the Navajo course so that you can pick it up as you go along.
The paragraph about "ł"is a little confusing so I would like to clarify: "ł" in Navajo and in Polish are two very different sounds. In Polish it represents "dark L", which sounds like English "l" but deeper. In Navajo the sound represents the same sound that is in Welsh "ll" and Zulu "hl"; it's produced by holding your tongue to your teeth like you're about to say "L" but you blow air through to get that almost hiss-like "l-sh" sound. Alternatively you can say "s" but hold your tongue tight to your teeth as you produce the sound, which has a similar effect but not as effective. You are correct that it is the same sound as the one at the end of the word for Nahuatl in the language of the same name, though.
I just looked it up and it seems like you’re right. Ł is /w/ in standard Polish but most Poles still understand words when it’s pronounced like /ɫ/, so avoiding dark L when wanting to pronounce regular L is still something learners need to keep in mind. https://en.m.wikibooks.org/wiki/Polish/Polish_pronunciation
Navajo pronunciation isn’t too difficult but it does require you to do things in ways that initially are not natural to most non-Navajo speakers, like vowel tones and aspirated consonants.
Just listening to Navajo helps a lot. Here are a couple of sites that can help beginners:
Navajo Word of the Day (inactive but the files are still working) https://navajowotd.com/category/word/
Daybreakwarrior's You Tube channel: https://www.youtube.com/channel/UCHS5AbSAL_SqDxHitopEwdA
I'd be careful with these two videos. The speaker (lady pronouncing the words) is not a native Navajo speaker. She sounds like an Apache speaker trying to speak Navajo.
I do not mean anything rude by this. Though, I will say that Apaches tend to have difficulties with pronouncing Navajo words. For example, ’ooljéé’, she does not pronounce the final glottal stop. This, from my experience, is a fairly common mistake made my Apache speakers.
Here is a link to a site where you can download keyboards for the various Athabaskan languages (scroll down to American South West): http://www.languagegeek.com/dene/keyboards/romdene.html#Southwest
Also comes with a PDF document to familiarise yourself with the layout beforehand.