It's very quiet on the bird front this time of year anyway as the nesting is all but finished, so no singing is needed. You should be hearing the Robin's sad, autumnal song any time now to September - very different from the loud upbeat spring song. I heard one singing a few notes last week, but it didn't last very long.
Robins are busy from April to August fighting, mating, nesting and bringing up their family and then moulting. The latter leaves them particularly vulnerable so they hide away until they have their smart autumn and winter feathers. They have the red all through the year, but apart it's not so bright as the winter/spring red, and the babies have brown speckled breasts.