Portuguese phonology

The phonology of Portuguese can vary considerably between dialects, in extreme cases leading to difficulties in intelligibility. This article focuses on the pronunciations that are generally regarded as standard. Since Portuguese is a pluricentric language, and differences between European Portuguese (EP) and Brazilian Portuguese (BP) can be considerable, both varieties are distinguished whenever necessary.

One of the most salient differences between European and Brazilian Portuguese is their prosody. European Portuguese is a stress-timed language, with reduction, devoicing or even deletion of unstressed vowels and a general tolerance of syllable-final consonants. Brazilian Portuguese, on the other hand, is of mixed characteristics, and varies according to speech rate, sex and dialect. At fast speech rates, Brazilian Portuguese is more stress-timed language, while in slow speech rates, it can be more syllable-timed. The accents of rural, southern Rio Grande do Sul and the Northeast (especially Bahia) are considered to sound more syllable-timed than the others, while the southeastern dialects such as the mineiro, in central Minas Gerais, the paulistano, of the northern coast and eastern regions of São Paulo, and the fluminense, along Rio de Janeiro, Espírito Santo and eastern Minas Gerais as well the Federal District, are most frequently essentially stress-timed. Also, male speakers of Brazilian Portuguese speak faster than female speakers and speak in a more stress-timed manner. and with a lighter reduction of unstressed vowels, less raising of pre-stress vowels, less devoicing and fewer deletions.

...
Wikipedia