Sephardi Hebrew (or Sepharadi Hebrew) is the pronunciation system for Biblical Hebrew favored for liturgical use by Sephardi Jewish practice. Its phonology was influenced by contact languages such as Spanish, Ladino, Arabic, Portuguese and Greek.
There is some variation between the various forms of Sephardi Hebrew, but the following generalisations may be made.
This last difference is the standard shibboleth for distinguishing Sephardi from Ashkenazi (and Yemenite) Hebrew. The differentiation between kamatz gadol and kamatz katan is made according to purely phonetic rules without regard to etymology, which occasionally leads to spelling pronunciations at variance with the rules laid down in Biblical Hebrew grammar books. For example, כָל (all), when unhyphenated, is pronounced "kal" rather than "kol" (in "kal 'atsmotai" and "Kal Nidre"), and צָהֳרַיִם (noon) is pronounced "tsahorayim" rather than "tsohorayim". This feature is also found in Mizrahi Hebrew, but is not found in Israeli Hebrew. It is represented in the transliteration of proper names in the Authorised Version, such as "Naomi", "Aholah" and "Aholibamah".
Sephardim differ on the pronunciation of bet raphe (ב, bet without dagesh). Persian, Moroccan, Greek, Turkish, Balkan and Jerusalem Sephardim usually pronounce it as [v], and this is reflected in modern Hebrew. Spanish and Portuguese Jews traditionally pronounced it as [b ~ β] (as do most Mizrahi Jews), though this is declining under the influence of Israeli Hebrew.
This may reflect changes in the pronunciation of Spanish. In medieval Spanish (and in Ladino), b and v were separate, with b representing a voiced bilabial stop and v realized as a bilabial fricative [β]. However, in Renaissance and modern Spanish, the sounds of the two letters have assimilated, and both are pronounced [β] (bilabial v) when following a vowel (or continuant) and as [b] otherwise (after a pause).
There is also a difference in the pronunciation of taw raphe (ת, taw without dagesh) .
Closely related to the Sephardi pronunciation is the Italian pronunciation of Hebrew, which may be regarded as a variant of it.
In communities from Italy, Greece and Turkey, he is not realized as [h], but as a silent letter. This is due to the influence of Italian, Ladino and (to a lesser extent) Greek, all of which lack the sound. This was also the case in early transliterations of Spanish-Portuguese manuscripts (e.g. Ashkibenu as opposed to Hashkibenu), but today he is consistently pronounced in these communities. (Basilectal Modern Hebrew shares this characteristic, but it is considered substandard.)
In addition to ethnic and geographical distinctions, there are some distinctions of register. Popular Sephardic pronunciation, for example in the Spanish and Portuguese community, makes no distinction between pataḥ and qameṣ gadol [a], or between segol, ṣere and sheva na [e]: this is inherited from the old Palestinian vowel notation. In formal liturgical use, however, many Sephardim are careful to make some distinction between these vowels, to reflect the Tiberian notation. (Compare the attempts of some Ashkenazim to use the pharyngeal sounds of ḥet and ayin in formal contexts such as Torah reading.)
There have been several theories on the origins of the different Hebrew reading traditions. The basic cleavage is between those who believe that the differences arose in medieval Europe and those who believe that they reflect older differences between the pronunciations of Hebrew and Aramaic current in different parts of the Fertile Crescent, that is to say Judaea, Galilee, Syria, northern Mesopotamia and Babylonia proper.
Within the first group of theories, Zimmels believed that the Ashkenazi pronunciation arose in late medieval Europe and that the pronunciation prevailing in France and Germany in the time of the Tosafists was similar to the Sephardic. His evidence for this was the fact that Asher ben Jehiel, a German who became chief rabbi of Toledo, never refers to any difference of pronunciation, though he is normally very sensitive to differences between the two communities.
The difficulty with the second group of theories is that we do not know for certain what the pronunciations of these countries actually were and how far they differed. Since the expulsion of the Jews from Spain in 1492, if not before, the Sephardic pronunciation of the vowels became standard in all these countries, ironing out any differences that previously existed. This makes it harder to adjudicate between the different theories on the relationship between today's pronunciation systems and those of ancient times.
Leopold Zunz believed that the Ashkenazi pronunciation was derived from that of Palestine in Geonic times (7th-11th centuries CE), while the Sephardi pronunciation was derived from that of Babylonia. This theory was supported by the fact that, in some respects, Ashkenazi Hebrew resembles the western dialect of Syriac while Sephardi Hebrew resembles the eastern, e.g. Eastern Syriac Peshitta as against Western Syriac Peshito. Ashkenazi Hebrew in its written form also resembles Palestinian Hebrew in its tendency to malē spellings (see Mater lectionis).
Others, including Abraham Zevi Idelsohn, believed that the distinction is more ancient, and represents the distinction between the Judaean and Galilean dialects of Hebrew in Mishnaic times (1st-2nd centuries CE), with the Sephardi pronunciation being derived from Judaean and the Ashkenazi from Galilean. This theory is supported by the fact that Ashkenazi Hebrew, like Samaritan Hebrew, has lost the distinct sounds of many of the guttural letters, while there are references in the Talmud to this as a feature of Galilean speech. Idelsohn ascribes the Ashkenazi (and, on his theory, Galilean) pronunciation of qamats gadol as /o/ to the influence of Phoenician: see Canaanite shift.
In the time of the Masoretes (8th-10th centuries CE) there were three distinct notations for denoting vowels and other details of pronunciation in biblical and liturgical texts. One was the Babylonian; another was the Palestinian; the third was the Tiberian, which eventually superseded the other two and is still in use today.
Of these, the Palestinian notation provides the best fit to the current Sephardi pronunciation: for example it does not distinguish between pataẖ and qamats, or between segol and tsere. (Similarly, the Babylonian notation appears to fit the Yemenite pronunciation.) The Tiberian notation does not quite fit any pronunciation in use today, though the underlying pronunciation has been reconstructed by modern scholars: see Tiberian vocalization. (A variant of the Tiberian notation was used by Ashkenazim, before being superseded by the standard version.)
By the time of Saadia Gaon and Jacob Qirqisani, the "Palestinian" pronunciation had come to be regarded as standard, even in Babylonia (for references, see Mizrahi Hebrew): this development roughly coincided with the popularisation of the Tiberian notation.
The accepted rules of Hebrew grammar were laid down in medieval Spain by grammarians such as Judah ben David Hayyuj and Jonah ibn Janah, and later restated in a modified form by the Kimhi family: the current Sephardic pronunciation largely reflects the system they laid down. By then the Tiberian notation was universally used, though it was not always reflected in pronunciation. The Spanish grammarians accepted the rules laid down by the Tiberian Masoretes, with the following variations.
Further differences from the Tiberian system are:
In brief, Sephardi Hebrew appears to be a descendant of the Palestinian tradition, partially adapted to accommodate the Tiberian notation and further influenced by the pronunciation of Arabic, Spanish and Judaeo-Spanish (Ladino).
When Eliezer ben Yehuda drafted his Standard Hebrew language, he based it on Sephardi Hebrew, both because this was the de facto spoken form as a lingua franca in the land of Israel and because he believed it to be the most beautiful of the Hebrew dialects. However, the phonology of Modern Hebrew is in some respects constrained to that of Ashkenazi Hebrew, including the elimination of pharyngeal articulation and the conversion of /r/ from an alveolar tap to a voiced uvular fricative.