Noise at work - Hearing health COTRAL hearing protection device after-sales service , our COTRAL Lab Noise Prevention Specialist is visiting the company. On From to If you have any questions or if your have experienced any difficulties with your COTRAL hearing protection device, please enter your name in the table below. An appointment will be organized. Please attend with: your COTRAL hearing protection device your impressions or your warranty. First name Job title/Department Preparation of a COTRAL solution - Doc No. 50314 Surname