Dakuten used in non-standard ways (like with vowels)?


Sometimes in manga I encounter dakuten used in unexpected ways. For example,
I've seen it used after あ. I wonder what effect it has on the pronunciation.
Does it basically mean that the voice is getting stronger\louder? Is this used
outside of manga too? Any other uncommon uses of dakuten I should be aware of?




  * あ゛ used to be commonly used in manga to express an exclamation -- "aagh!" or something like that. I feel it has become less common (if not rare) these days. え゛、い゛、お゛、の゛ and so on are sometimes used in a similar way. You may see them in casual blogs and tweets, but never in formal documents.
  * ヴ is commonly used to express the 'v' sound in loanwords (eg ヴァイオリン instead of バイオリン). It's usually in katakana, but in manga we sometimes see hiragana う゛ [for various reasons](https://japanese.stackexchange.com/q/15108/5010).




  * あ゛ used to be commonly used in manga to express an exclamation -- "aagh!" or something like that. I feel it has become less common (if not rare) these days. え゛、い゛、お゛、の゛ and so on are sometimes used in a similar way. You may see them in casual blogs and tweets, but never in formal documents.
  * ヴ is commonly used to express the 'v' sound in loanwords (eg ヴァイオリン instead of バイオリン). It's usually in katakana, but in manga we sometimes see hiragana う゛ [for various reasons](https://japanese.stackexchange.com/q/15108/5010).

