Kelabit phonology

Vowels are. All consonants but the aspirated voiced stops are lengthened after stressed. Stress generally occurs on the penultimate syllable.

Kelabit is notable for having "a typologically rare series of true voiced aspirates" (that is, not breathy voice/murmured consonants; for some speakers they are prevoiced) along with modally voiced and tenuis consonants but without an accompanying series of voiceless aspirates. It is the only language known to have voiced aspirates or murmured consonants without also having voiceless aspirated consonants, a situation that has been reconstructed for Proto-Indo-European. (See glottalic theory.)

At the end of a word, is pronounced. For some speakers, is affricated; in neighboring Lun Dayeh, the reflex of this consonant is an unaspirated affricate. is rare, and is not attested from all dialects.

The flap is alveolar. It's not clear if and the other coronal sonorants are alveolar like  or dental like.

The aspirated voiced series only occurs intervocalicly, and may have arisen from geminate consonants. They are at least impressionistically twice as long as other stops. They vary with under suffixation, with  occurring where other consonants would be allophonically geminated:
 * 'to fell' > 'fell it!'
 * 'back (n)' > 'to be left behind'

There are several arguments for analyzing the aspirated voiced consonants as segments rather than as consonant clusters:
 * There are no (other) clusters allowed in the language. Some languages allow only geminate consonants as clusters, but there are no (other) phonemic geminates in Kelabit. In some related languages, such as Ida'an, the reflexes of these sounds clearly do behave as clusters.
 * The syllable break occurs before the consonants (that is,, and not in the middle , which is the behaviour of consonant clusters (including geminates) in related languages that allow them. lower to  before any non-glottal coda consonant. They do not lower before the aspirated voiced consonants, again suggesting they are not consonant clusters.

The aspirated voiced series does not appear in all dialects of Kelabit or Lun Dayeh: