The Gulf Coast Toad (Incilius nebulifer) is one of the most common amphibians in the eastern 2/3 of the state of Texas. It is a common resident of residential backyards and its trilling calls can be heard in most large cities east of the Trans-Pecos on any rainy summer night.
This toad was photographed and recorded in Karnes County, Texas, after some heavy rains the preceding night.
The call is a long dry trill. In this recording, the toad picture above calls and then another individual on the opposite bank responds.
The bleating call heard in the background are Western Narrow-mouthed Toads (Gastrophryne olivacea).
Here is the spectrogram for the first call in that recording -
This Gulf Coast Toad was calling along the edge of a flooded creek in Real County.
You can hear him call, another nearby toad replies, and he responds again. This staggering or alternating of calls is very common in this species.
Here's a video of a Gulf Coast Toad from Medina county, Texas.
You can hear him calling and some other Gulf Coast Toads responding. You also hear Cope's Gray Treefrogs (Hyla chrysoscelis), Blanchard's Cricket Frogs (Acris blanchardi), Great Plains Narrowmouthed Toads (Gastrophryne olivacea) and Rio Grande Leopard Frogs (Lithobates berlandieri) in the background.