Memories of Manfred Schroeder at Bell Telephone Laboratories: 1955–1987. Free

Manfred joined Bell Labs in late 1954 and I joined in the middle of 1955. We both retired in 1987. We and our families became close friends. This was a golden age of research at Bell Labs. ATT, a regulated monopoly with a steady source of income and a great need for new technology, well supported the research. In 1969 Manfred took a second job as head of the Third Physical Institute (Acoustics) at Goettingen, Germany, but continued working at Bell Labs, interacting closely with Bishnu Atal. Manfred’s speech work led to encodings to reduce the bits needed to transmit speech. Manfred showed one does not need to encode the parts of sounds which the ear does not hear due to masking by the ear itself. He was strongly interested in number theory and used it to design colorless diffusing panels for auditoriums. He developed reproducible white noise signals to test auditoriums. He also designed colorless digital reverberators for music. Manfred and I were incredibly lucky to have lived in such an exciting time and worked at such great institutions.