The Wood Thrush's easily recognized, flute-like ee-oh-lay is actually only the middle phrase of a three-part song. It learns the phrase from other Wood Thrushes and sings several variants with 2 to 10 loud, clear notes. Combining those with 1–3 variants of the low, soft notes of the introductory phrase and 6–12 variants of the final higher-pitched complex trill, a male can easily sing over 50 distinct songs. Individuals can be identified by the repeating order they sing their variants of the middle phrase in song after song.
A staccato bup-bup-bup call signals mild distress, but rises in pitch and grows louder and more complex with increasing agitation until it becomes a distinctive, machine-gun-like pit-pit-pit alarm. This call accompanies territory or nest defense. The male sometimes chatters a pit-pit call during nest building, when it may be part of mate guarding.
During aggressive displays, Wood Thrushes may snap the mandibles of the bill together.