How to get a visualbell in vim on mac?
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I am calling vim from the terminal on Lion OSX.  I want to get rid of the audio bell and use only a visualbell.  The documentation seems to indicate that I can accomplish this with `:set vb`.  Once I issue `:set vb` the folling settings result:

    :set vb? t_vb?

gives

    visualbell
    t_vb=
 
and the flash obviously does not work. The documentation indicates that `t_vb` should be `<Esc>|f` by default. It is not. I have tried to set `t_vb` directly but I cannot figure out what it should be to produce the flash.

Also note that it does not work with mvim either.  But in the case of mvim it defaults to `t_vb=^[|f` to no avail.

Does anyone have a visualbell working on a mac?  If so how was this accomplished?