Making distance/space between notes above a syllable smaller

[b.a.g.hillen]

Is it possible in Lilypond to make the distance/space between two or three
notes above a syllable smaller?
In the example see the slurs g(bes) and bes(c bes) with 2 or 3 notes.

\version "2.18.2"
eenVoice = \relative c'' {\key bes \major 
   \cadenzaOn   % zet barlines uit
   \override Staff.TimeSignature #'stencil = ##f
   \hide Stem
   d,4 f g f g (bes) bes^- bes (c bes) a g^- \bar":|."
}
verseOne = \lyricmode {
    O -- ver heel de aar -- de klinkt hun roep. 
}
\score {
  <<
    \new Voice = "one"  {
    \eenVoice
}
    \new Lyrics \lyricsto "one"{
    \verseOne
}
  >>
}

Regards,

Ben Hillen