Classifications for Dolby Laboratories Licensing Corp

H04N

Pictorial Communication, E.g. Television

H04S

Stereophonic Systems 

G10L

Speech Analysis Or Synthesis; Speech Recognition; Speech Or Voice Processing; Speech Or Audio Coding Or Decoding

H04R

Loudspeakers, Microphones, Gramophone Pick-ups Or Like Acoustic Electromechanical Transducers; Deaf-aid Sets; Public Address Systems

G06F

Electric Digital Data Processing