Western Khmer, also known as Chanthaburi Khmer, is the dialect of the Khmer language

Khmer language

Khmer , or Cambodian, is the language of the Khmer people and the official language of Cambodia. It is the second most widely spoken Austroasiatic language , with speakers in the tens of millions. Khmer has been considerably influenced by Sanskrit and Pali, especially in the royal and religious...

 spoken by the Khmer people

Khmer people

Khmer people are the predominant ethnic group in Cambodia, accounting for approximately 90% of the 14.8 million people in the country. They speak the Khmer language, which is part of the larger Mon–Khmer language family found throughout Southeast Asia...

 native to the Cardamom Mountains

Cardamom Mountains

The Krâvanh Mountains, literally the "Cardamom Mountains" , is a mountain range in the south west of Cambodia, jutting into southeastern Thailand.-Location and description:...

 on both sides of the border between western Cambodia

Cambodia

Cambodia , officially known as the Kingdom of Cambodia, is a country located in the southern portion of the Indochina Peninsula in Southeast Asia...

 and eastern Central

Central Thailand

Central Thailand is a region of Thailand, covering the broad alluvial plain of the Chao Phraya River. It is separated from North-East Thailand by the Phetchabun mountain range, and another mountain range separates it from Myanmar to the west. In the north it gently changes into the more hilly...

 Thailand

Thailand

Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...

 (Chanthaburi Province

Chanthaburi Province

Chanthaburi is a province of Thailand. It is located in the east of Thailand, at the border to Battambang and Pailin of Cambodia and the shore to the Gulf of Thailand...

). Developing in an historically isolated region, Western Khmer is the only dialect of modern Khmer to conserve the Middle Khmer phonation

Phonation

Phonation has slightly different meanings depending on the subfield of phonetics. Among some phoneticians, phonation is the process by which the vocal folds produce certain sounds through quasi-periodic vibration. This is the definition used among those who study laryngeal anatomy and physiology...

 contrast of breathy voice

Breathy voice

Breathy voice is a phonation in which the vocal cords vibrate, as they do in normal voicing, but are held further apart, so that a larger volume of air escapes between them. This produces an audible noise...

 versus modal voice

Modal voice

Modal voice is the vocal register used most frequently in speech and singing in most languages. It is also the term used in linguistics for the most common phonation of vowels...

that has been all but lost in the other dialects.