Nivkh phonology

Consonants
The labial fricatives are weakly articulated, and have been described as both bilabial and labiodental. The palatal stops may have some degree of affrication, as

Nivkh features a process of consonant alternation, in which morpheme-initial stops alternate with fricatives and trills:

This occurs when a morpheme is preceded by another morpheme within the same phrase (e.g. a prefix or an adjunct), unless the preceding morpheme ends itself in a fricative or trill, or in a nasal or.
 * 'soup'
 * 'duck soup'
 * 'kind of seal soup'
 * but: 'bear soup'

Only the morpheme-initial position is affected: other clusters ending in a stop are possible within a morpheme (e.g. "man").

In some transitive verbs, the process has been noted to apparently run in reverse (fricatives/trills fortiting to stops, with the same distribution). This has been taken a distinct process, but has also been explained to be fundamentally the same, with the citation form of these verbs containing an underlying stop, lenited due to the presence of a former i- prefix (which still survives in the citation form of other verbs, where it causes regular consonant alternation). Initial fricatives in nouns never change.

After nasals or, the unaspirated stops become voiced. Unlike consonant alternation, this occurs also within a morpheme. The Amur dialect deletes some word-final nasals, which leads to voiced stops occurring also word-initially.

Vowels
The vowel system of Nivkh is unusual, being described by Ian Maddieson as "defective." It is actually a rotated system in which a gap in the mid front region of the vowel space is compensated for by moving vowels around. The centralised has been described by Maddieson (1984) as complementing a gap caused by the lack of an ordinary mid front vowel.

The mid front vowel expected in a five-vowel system may have in the past developed into a close-to-mid front unrounded diphthong, represented in Maddieson's description of the language as.

Stress
Stress can fall on any syllable, but tends to be on the first; there is dialectal variation, and minimal pairs distinguished by stress seem to be rare.