  Exploding granules have drawn renewed interest because of their interaction
with the magnetic field. Especially the newly forming downflow lanes developing
in their centre seem to be eligible candidates for the intensification of
magnetic fields. We analyse spectroscopic data from two different instruments
in order to study the intricate velocity pattern within the newly forming
downflow lanes in detail. We aim to examine general properties of a number of
exploding granules. To gain a better understanding of the formation process of
the developing intergranular lane in exploding granules, we study the temporal
evolution and height dependence of the line-of-sight velocities at their
formation location. Additionally, we search for evidence that exploding
granules act as acoustic sources. We investigated the evolution of several
exploding granules using data taken with the Interferometric Bidimensional
Spectrometer and the Imaging Magnetograph eXperiment. Velocities for different
heights of the solar atmosphere were determined by computing bisectors of the
Fe I 6173.0{\AA} and the Fe I 5250.2{\AA} lines. We performed a wavelet
analysis to study the intensity and velocity oscillations within and around
exploding granules. We also compared our findings with predictions of numerical
simulations. We found that exploding granules have significantly longer
lifetimes than regular granules. Exploding granules larger than 3.8 arcsec form
an independent intergranular lane during their decay phase, while smaller
granules usually fade away or disappear into the intergranular area. For all
exploding granules that form a new intergranular downflow lane, we find a
temporal height-dependent shift with respect to the maximum of the downflow
velocity. Our suggestion that this results from a complex atmospheric structure
within the newly forming downflow lane is supported by the simulations.
