"Our research builds on previous studies, which have found that spelling can interfere with how learners pronounce individual vowels and consonants of a non-native language."
This matches very well with my own personal observations. Most language instruction focuses very heavily on written instruction, which can be damaging early on. When you're just starting out a new language, you should learn the sounds by mimicking native speakers, not by reading letters off a page. When reading, your preconceptions of how those strings of letters would be pronounced in your own native language can interfere with correct pronunciation.
Once you've got the pronunciation of the basic sounds of the new language down correctly, you can start using written materials.
This matches very well with my own personal observations. Most language instruction focuses very heavily on written instruction, which can be damaging early on. When you're just starting out a new language, you should learn the sounds by mimicking native speakers, not by reading letters off a page. When reading, your preconceptions of how those strings of letters would be pronounced in your own native language can interfere with correct pronunciation.
Once you've got the pronunciation of the basic sounds of the new language down correctly, you can start using written materials.