  The fluctuation-dissipation relation (FDR) is measured on the dielectric
properties of a gel (Laponite) and of a polymer glass (polycarbonate). For the
gel it is found that during the transition from a fluid-like to a solid-like
state the fluctuation dissipation theorem is strongly violated. The amplitude
and the persistence time of this violation are decreasing functions of
frequency. Around $1Hz$ it may persist for several hours. A very similar
behavior is observed in polycarbonate after a quench below the glass transition
temperature. In both cases the origin of this violation is a highly
intermittent dynamics characterized by large fluctuations. The relevance of
these results for recent models of aging are discussed.
