After wintering from southern New England southwards, Pied-billed Grebes return to the northern freshwater marshes and lakes where they breed and nest on floating platforms of vegetation. It is here, on their nesting grounds, that they are most vocal, with both males and females producing songs (the female’s is a bit softer). At this time of year, you often hear a Pied-billed Grebe before you see it.
When singing, a Pied-billed Grebe submerges its breast and neck to varying degrees. Its primary song has three parts. During the first part, the grebe retracts its head slightly with every note. During second and third parts, it moves its bill up toward the end of each note. David Sibley describes this extremely variable call as sounding something like “ge ge gadum gadum gadum gaum gaom gwaaaaaow gwaaaaaow gaom.” You can hear it and describe it in your own words by going to http://www.allaboutbirds.org/guide/pied-billed_grebe/sounds.