During my first week as a federal prosecutor of sexual abuse crimes against children, one of my colleagues told me her chief coping mechanism: Turn the sound off when you have to watch a video multiple times. This advice scared me. I imagined children screaming, crying and shrieking in pain — the stuff of nightmares.

My office is responsible for investigating and prosecuting such crimes, namely the production, possession and trafficking of child pornography. My first case file contained multiple CDs and DVDs showing a young girl being sexually abused by her father, who filmed his crimes with a handheld camera. Despite my colleague’s warning, I knew I couldn’t remain deaf during my first pass at the evidence. I went to our forensic computer lab and braced myself.

But all I heard was silence. The 5-year-old girl said nothing — not even a sob. Disturbed, I continued to watch each video with the sound on. I tried to beat back the silence by turning the volume up as high as it could go. The quiet was too deafening, too defeating to accept. Surely, these children must make a sound?