People with schizophrenia often have a wide variety of hallucinations that are rich in content. Patients may hear someone speaking to them out of thin air, such as commenting on themselves, threatening them, verbally abusing them, and ordering them to do something. They may also hear sounds from outside objects or animals, such as birds chirping, dogs barking, or people walking. There are true hallucinations and false hallucinations in schizophrenia. True hallucinations are when the patient hears sounds from the objective world, and false hallucinations are when the patient hears sounds in his head.