When a singer speaks rather than sings.

[ivan . k . kuznetsov]

In a vocal part I am notating, while the singer mostly
sings notated pitches, there are a few parts
where the singer will speak text in notated
rhythm.

When this is done is scores that I have seen,
sometimes it is done with just stems, flags and
beams (but no note heads) such as in 
the Charles Ives song "Charlie Rutlage".
I have also seen it just written with 
the note heads as "x"s on a stave (such as
with a percussion score).  How does
one go about implementing either method
in lilypond?  I do prefer the latter, though.

Thank you for your help.