Spectral optimization of audio masking waveforms

• Main Authors: Wax, Aric J, Gauger, Jr., Daniel M, Lee, Daniel K
• Format: Patent
• Language: English
• Published: 23.07.2019
• Subjects: ACOUSTICS; ACOUSTICS NOT OTHERWISE PROVIDED FOR; BANDAGES, DRESSINGS OR ABSORBENT PADS; DEAF-AID SETS; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF,TUBULAR STRUCTURES OF THE BODY, E.G. STENTS; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; FILTERS IMPLANTABLE INTO BLOOD VESSELS; FIRST-AID KITS; FOMENTATION; HUMAN NECESSITIES; HYGIENE; LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKEACOUSTIC ELECTROMECHANICAL TRANSDUCERS; MEDICAL OR VETERINARY SCIENCE; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING,NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; MUSICAL INSTRUMENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; PHYSICS; PROSTHESES; PUBLIC ADDRESS SYSTEMS; SOUND-PRODUCING DEVICES; SPEECH ANALYSIS OR SYNTHESIS; SPEECH OR AUDIO CODING OR DECODING; SPEECH OR VOICE PROCESSING; SPEECH RECOGNITION; TREATMENT OR PROTECTION OF EYES OR EARS

A system for masking audio signals includes a microphone for generating an ambient audio signal representing ambient noise, a speaker for rendering masking audio, and a processor in communication with the microphone and the speaker. The processor performs spectral analysis on the ambient audio signal from the microphone to determine a spectral envelope of the ambient noise, adjusts a frequency response of an optimizing filter based on the spectral envelope, applies the optimizing filter to a baseline masking waveform, producing an output waveform with relative spectral distribution matching the ambient noise, and provides the output waveform to the speaker.