unstressed syllables generally merges with and so effect is pronounced like affect, and abbot and rabbit rhyme. The quality of the merged vowel varies considerably based on the environment but is typically more open, like [ə], in word-initial or word-final position, but more close, like [ɪ~ɨ], elsewhere. Raising of pre-voiceless : Many speakers split the sound based on whether it occurs before a voiceless consonant and so in rider, it is pronounced , but in writer, it is raised to (because is a voiceless consonant while is not). Thus, words like bright, hike, price, wipe, etc. with a following voiceless consonant (such as ) use a more raised vowel sound compared to bride, high, prize, wide, etc. Because of this sound change, the words rider and writer , for instance, remain distinct from one another by virtue of their difference in height (and length) of the diphthong's starting point (unrelated to both the letters d and t being pronounced in these words as alveolar flaps ). The sound change also applies across word boundaries, though the position of a word or phrase's stress may prevent the raising from taking place. For instance, a high school in the sense of "secondary school" is generally pronounced ; however, a high school in the literal sense of "a tall school" would be pronounced . The sound change began in the Northern, New England, and Mid-Atlantic regions of the country, and is becoming more common across the nation. Many speakers in the Inland North, Upper Midwestern, and Philadelphia dialect areas raise before voiced consonants in certain words as well, particularly , and . Hence, words like tiny, spider, cider, tiger, dinosaur, beside, idle (but sometimes not idol), and fire may contain a raised nucleus. The use of , rather than , in such words is unpredictable from the phonetic environment alone, but it may have to do with their acoustic similarity to other words that with before a voiceless consonant, per the traditional Canadian-raising system. Some researchers have argued that there has been a phonemic split in those dialects, and the distribution of the two sounds is becoming more unpredictable among younger speakers. Some speakers from California, other Western states including those in the Pacific Northwest, and the Upper Midwest realize final as when ("short i") is raised to become ("long ee") before the underlying is converted to , so that coding, for example,