The Noba are believed to have spoken a Nubian language. The Nubian language is not related Meroitic.Welsby in The Kingdom of Kush wrote, "Early scholars of the [Meroitic] language hoped that it may have been related to Old Nubian but this has been shown not to be the case, although both are agglutinative, lack gender and the place of inflexions taken by post-positions and suffixes. Whether it was related to the language of the Kerma culture is another unknown, as no inscriptions in Kerman have come to light"(p.190).
Lazlo Torok, in The Kingdom of Kush:Handbook of the Napatan-Meroitic Civilization , wrote "Since so far no bilingual text has been discovered nor any related language found, very little of Meroitic can be understood. Some linguists see a relationship between Berber and Chadic on the one hand and Meroitic, on the other. Others regard it as related to Nubian. On geographical grounds, it has been suggested that Meroitic may be related to the following language groups(in describing order of probability). Eastern Sudabic; Nilo-Saharan; Cushitic/Omotic; Kordofanian. The efforts based on such assumptions produced, however, very few results, if any. While the linguistic classification of Meroitic remains obscure, there is hardly any doubt that it was originally spoken in the northern Butana" (p.50).As you can see Meroitic has not been found to be related to Nubian, other languages in the Nilo-Saharan family ,or any other language spoken in the area.
The Nubians or Nobatai lived in the area from Aswan to Maharraqa called the Dodekaschoenas which was first under the rule of the Ptolemies and later the Romans. Most researchers believe that by 200 BC most of the region was occupied by Nubians. Ptolemy, noted that in the mid-2nd Century AD that the Nubae lived on the Westside of the Nile, and that they were not subjects of the Kushites.
David O'Connor makes it clear in Ancient Nubia: Egypt's Rival in Africa (1993), that the Nubians or Nobatai "adopted a Romano-Egyptian culture very different from that of Meroitic Lower Nubia" (p.72).
Welsby, in The Kingdom of Kush,also believes that the Dodekaschoenas was not fully occupied by Meroites. But there were some Meroites in the major cities.
When the Romans left the area in AD 270, the Diocletian agreement was between the Nobatae and the Romans, not the Romans and Kushites. This makes it clear that the Nubian speakers were Western oriented and not Meroites. In fact the oldest known Noba inscriptions were written in Greek and Coptic, not Meroitic.
The Noba/Nubians were enemies of the Kushites of Meroe. Above is a bound Nubian captive. This artifact was discovered at Meroe in 1911. On the chest of the figure are the following inscriptions: Qo-ne Qore nob o lo. This reads: " The honorable Nubian King arrive(d) as a captive". Another small brone Noba figure was inscribed with the words : E de qe Nob. This inscription reads: "Act indeed to register the Noba (prisoner)".