The famous screams of Tom the cat were recorded by the show's co-creator, William Hanna.

William Hanna co-created Tom and Jerry and directed many of the original cartoons. He provided the voice for Tom's screams, gasps, and growls from 1942 to 1958. This information is documented in the book A Cast of Friends by his partner Joseph Barbera.Hanna recorded these sounds by standing very close to a microphone. He used his own voice instead of using real animal sounds or machines. MGM studio logs and staff interviews confirm that Hanna was the source of these uncredited vocal effects.Audio engineers at MGM used analog reel-to-reel tape recorders to capture Hanna's voice. Sound designer Bob Gentle explained that these recordings were sometimes layered or echoed. This helped the sounds match the fast-paced movement of the animation.Modern cartoons often use digital sound libraries or animal recordings for sound effects. Tom and Jerry relied on human performance to make the character feel more expressive. Hanna's specific vocal style became a signature part of the show's identity.