Strange sound

Just now I went to office today alone. While doing the small business, I heard some strange sound. Like someone painfully scream. I can very clearly the sound. Quickly finish my small business, wash hand and run back to my seat. I saw one of my Malay colleagues, I told her what I heard and I drag her to toilet again. But both of us cannot hear the sound anymore. Yikes, so scary lar. I got to pray more now.