In Australian linguistics

Australian Aboriginal languages

The Australian Aboriginal languages comprise several language families and isolates native to the Australian Aborigines of Australia and a few nearby islands, but by convention excluding the languages of Tasmania and the Torres Strait Islanders...

, the peripheral consonants are a natural class

Natural class

In phonology, a natural class is a set of sounds in a language that share certain phonetic features. The sound system of every language includes several natural classes, each distinguished from other classes by certain features. A given natural class is described using the minimum number of...

 encompassing consonants articulated at the extremes of the mouth: bilabials

Bilabial consonant

In phonetics, a bilabial consonant is a consonant articulated with both lips. The bilabial consonants identified by the International Phonetic Alphabet are:...

and velars

Velar consonant

Velars are consonants articulated with the back part of the tongue against the soft palate, the back part of the roof of the mouth, known also as the velum)....

. That is, they are the non-coronal consonant

Coronal consonant

Coronal consonants are consonants articulated with the flexible front part of the tongue. Only the coronal consonants can be divided into apical , laminal , domed , or subapical , as well as a few rarer orientations, because only the front of the tongue has such...

s. In Australian languages, these consonants pattern together both phonotactically

Phonotactics

Phonotactics is a branch of phonology that deals with restrictions in a language on the permissible combinations of phonemes...

 and acoustically

Acoustic phonetics

Acoustic phonetics is a subfield of phonetics which deals with acoustic aspects of speech sounds. Acoustic phonetics investigates properties like the mean squared amplitude of a waveform, its duration, its fundamental frequency, or other properties of its frequency spectrum, and the relationship...

.

	Bilabial Bilabial consonant In phonetics, a bilabial consonant is a consonant articulated with both lips. The bilabial consonants identified by the International Phonetic Alphabet are:...		Velar Velar consonant Velars are consonants articulated with the back part of the tongue against the soft palate, the back part of the roof of the mouth, known also as the velum)....
Stop Stop consonant In phonetics, a plosive, also known as an occlusive or an oral stop, is a stop consonant in which the vocal tract is blocked so that all airflow ceases. The occlusion may be done with the tongue , lips , and &...	p	b	k	ɡ
Nasal Nasal consonant A nasal consonant is a type of consonant produced with a lowered velum in the mouth, allowing air to escape freely through the nose. Examples of nasal consonants in English are and , in words such as nose and mouth.- Definition :...	m		ŋ
Semivowel Semivowel In phonetics and phonology, a semivowel is a sound, such as English or , that is phonetically similar to a vowel sound but functions as the syllable boundary rather than as the nucleus of a syllable.-Classification:...	w

Phonotactics

Australian languages typically favour peripheral consonants word- and syllable-initially, while they are not allowed or rare word- and syllable-finally. This is diametrically opposed to the apicals

Apical consonant

An apical consonant is a phone produced by obstructing the air passage with the apex of the tongue . This contrasts with laminal consonants, which are produced by creating an obstruction with the blade of the tongue .This is not a very common distinction, and typically applied only to fricatives...

.

Acoustics

In Martuthunira

Martuthunira language

-Phonology:Martuthunira has a fairly standard Australian phonology. R.M.W. Dixon uses it as a prototypical example in his 2002 book Australian Languages: Their nature and development.-Consonants:The laminal stop has a voiced allophone between vowels....

, the peripheral stops /p/ and /k/ share similar allophony. While the other stops may be voiced between vowels or following a nasal, the peripherals are usually voiceless.