A foreign accent is obviously influenced by the native language of the speaker. What I'm wondering is if there's been any research on common traits of foreign accents across languages, that one could find even when not being familiar with the phonology of the language being spoken nor the native language of the speaker, something that is common to not speaking your own language. I'm thinking something like hesitations or phonological inconsistencies.
Edit: The reason for this question, I must admit, is that hearing people speak languages other than their native language really annoys me. I wish it didn't, and I'm wondering if there's anything to it other than me being judgmental. Hearing a person first speak a foreign language and then switch to their native language I am often struck by how the way they speak their native language is so much more natural and immediate, even when their vocabulary and pronunciation of the foreign language are at near-native level. This is all of course very impressionistic, so it'd like to read what's been written about it, except I don't know how or where to look for it.