I am a professional orchestral trombonist. Trombone is THE loudest non amplified classical instrument, clocking in at about 80dB to 114dB (That is louder than a lawn mower, but perhaps not musical as a lawn mower). As you can imagine, having me as a neighbor might be annoying at times. I decided to make a walk in closet into a practice room equipped with sound absorbing panels and acoustical insulation. The last and most difficult part of this design was the window. How could I prevent the sound from going out? I googled "acoustic window inserts" and up came this company. I called, and began the process of deciding. After doing a considerable amount of research with musician, acousticians, neighbors, and interior designers, I pulled the trigger. Since installation I have not heard a single remark from my neighbors. In fact, they may think I quit practicing altogether! Special thanks to Shane and Carissa - they were very patient and helpful in the process. I would recommend these window inserts to anyone and especially musicians!