The , commonly called , is a group of the Japanese dialects spoken in the Tà Âhoku region, the northeastern region of Honshà «. Toward the northern part of Honshà «, the Tà Âhoku dialect can differ so dramatically from standard Japanese that it is sometimes rendered with subtitles for intelligibility in the nationwide media and it has been treated as the typical rural dialect in Japanese popular culture.
A notable linguistic feature of the TÃ Âhoku dialect is its neutralization of the high vowels "i" and "u" (Standard and ) after coronal obstruents, so that the words , ('soot'), and ('lion') are rendered homophonous, where they would have been distinct in other dialects. In light of this, TÃ Âhoku dialect is sometimes referred to as . The vowels tend to be neutralized to in Northern TÃ Âhoku dialect and in Southern TÃ Âhoku dialect.
In addition, all unvoiced stops become voiced intervocalically, rendering the pronunciation of the word ('trained rabbit') as . However, unlike the high-vowel neutralization, this does not result in new homophones, as all voiced stops are prenasalized, meaning that the word ('corner') is pronounced . This is particularly noticeable with , which is nasalized fully to with the stop of the hard "g" almost entirely lost, so that ('strawberry') is pronounced . Standard Japanese can do this with too (see Japanese phonology), but not with the other stops. This distribution of medial voicing and prenasalization is thought to be a conservative pronunciation reflecting the original Old Japanese state.
The consonant inventory is identical to that of Standard Japanese but with a different distribution. In Standard Japanese, the palatal series was produced with palatalisation of alveolar consonants before the front vowel and the semivowel ; â , â , â . However, in the Tà Âhoku dialect they were formed by the palatalisation of and and the semivowel ; â , â ( â ; â ) and a shift of which was formed by palatalisation of before and the semivowel , towards ( â ).
In grammar, a volitional and presumptive suffix - or - is widely used in the region. It is a transformation of -, a conjugated form of an archaic suffix -. Since the 2011 TÃ Âhoku earthquake and tsunami, a slogan ("Let's buckle down!") has often been used in the disaster area.
A directional particle is also widely used in the region. It is a transformation of ('direction') and almost equivalent to standard or . A Muromachi period proverb "Kyà  , Tsukushi , Bandà  " says that the particle was once widely used in Kanto region.
The TÃ Âhoku dialects can be broken down geographically and by former domains:
In addition, the Eastern Kantà  dialects and the coastal dialects of Hokkaidà  have many Tà Âhoku features.
The vowel systems of the Izumo (also called Umpaku) and Tà Âhoku dialects exhibit several shared phonetic characteristics, such as centralized /i/ and /u/ and elevated /e/ and /o/, which make these vowels resemble each other more closely than those in other Japanese dialects. This centralization and elevation have caused vowel mergers in central Izumo and Tà Âhoku, indicating a historical linguistic change likely propagated from Izumo to the northeast via coastal migration. Archaeological findings, including corner-projected mound burials from 100âÂÂ250 AD in the Noto Peninsula and Toyama Prefecture, provide evidence for early Izumo influence in these areas. This implies that the distinctive vowel systems of Izumo likely spread to these regions during the Mid to Late Yayoi period. However, the Izumo-style tonal systems (Gairin A and Gairin B) had not yet developed then, as they are not present in the dialects of the Noto Peninsula and Toyama.
Elisabeth de Boer arguments in favour of an Izumo/Tà Âhoku branch within the Japanese dialects and that pre-existing trade contacts after the defeat of the Emishi in Tà Âhoku paved the way for immigration to the area. The blurred dialectal transitional area that extends for more than in southern Niigata may be due to immigrants with two different tone systems arriving from two different directions: part of them coming from the coast (Izumo) and the other part from the central highlands (Chà «bu).
Further migration from Izumo to the TÃ Âhoku region likely occurred after the development of the Gairin B tonal innovations. The existence of both Gairin A and Gairin B tonal systems in northern TÃ Âhoku suggests multiple migration waves. Historically, political and economic conditions in Izumo fluctuated between the eastern and western areas. The more advanced Gairin B tonal innovations originated in western Izumo and gradually spread eastward. This is reflected in TÃ Âhoku, where some areas still exhibit a blend of tonal systems.
Migration patterns during the Yayoi period saw rice farmers from western Japan moving to northern Honshà «. Early Yayoi settlements in coastal areas such as Ishikawa, Toyama, and western Niigata date back to around 300 BC. However, there is no direct evidence connecting these early settlers to Izumo. Clear indications of Izumo-style influence emerge later, especially through burial mounds dated 100âÂÂ250 AD. Migration into the Tà Âhoku region in the late 6th century matches archaeological evidence of the arrival of a new population similar to Kofun cultures found elsewhere in Japan. Prior to this, northern Tà Âhoku experienced a population decline as the Epi-Jomon people moved towards Hokkaidà Â. This new population, possibly from Izumo, spread swiftly across northern Tà Âhoku due to the regionâÂÂs sparse population, preserving the Izumo-style tone system there better than in southern and central Tà Âhoku, where there was more linguistic and dialectal interference. The relatively low internal diversity of Tà Âhoku dialects can be attributed to the later spread of Japanese northeastward compared to other mainland regions of Japan.