A sound-volume prediction apparatus acquires model information on an electronic device and positional information on an air intake section and/or an air-exhaust section of the electronic device. Furthermore, by using the model information and the positional information, the sound-volume prediction apparatus extends a sound ray that indicates a transmission route of sound generated by a sound source inside the electronic device toward the air-intake section and/or the air-exhaust section from the position of the sound source until the sound ray reaches the outside of the electronic device. The sound-volume prediction apparatus predicts sound transmission characteristics inside the electronic device by using geometric information on the flow path of the extended sound ray.