Automatic Sound-Leveling Device To Reduce Noise-Related Hearing Loss

Technology #13118

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John G. Harris
Colleen G. Le Prell
Qing Yang
Managed By
Richard Croley
Assistant Director 352-392-8929
Patent Protection
US Patent 8,804,975


The University of Florida is seeking companies interested in commercializing an automatic leveling device that will reduce the risk of noise-induced hearing loss when listening to audio sounds. Typical music files contain a large dynamic range of sound levels. Listeners will typically adjust the volume such that they can comfortably enjoy the lowest or average sound levels causing potential hearing risk during the loudest sound levels. The risk becomes even greater when these loud levels are compounded with extended listening time, which is common with today’s mp3 players with hard disks containing, literally, days of music. Researchers at the University of Florida have developed a device the effectively brings the dynamic range of different types of audio to a safe level without distorting the quality.


Digital audio file manipulation to be integrated into any music player or file organizer such as mp3 players, CDs, or DVDs


  • Reduces the dynamic range of music without any noticeable distortion or other degradation effects
  • Normalizes the sound power throughout the audio file, automatically adjusting as the sound changes
  • Brings the dynamic range of sound into an appropriate level, providing a safer listening environment without loss of audio quality
  • Easily accommodated by devices currently in use, allowing for simple incorporation into the market place
  • Lessens the intensity of volume during pitch changes, reducing the risk of noise-related hearing loss


This invention is a device and algorithm for effectively altering the sound level during an audio file to reduce the risk of hearing loss without losing sound quality. The leveling algorithm could be used as an offline post-processing step that can be applied to the sound on CDs and DVDs before they are manufactured or applied to music and video files before they are downloaded over the internet or cellular phone networks. Alternative applications could be as a real-time algorithm embedded in music players, radios or cellular phones, or as a part of larger sound amplification systems in automobiles, discos or concert halls. This system has been successfully tests with numerous subjects have listened to hours of our leveled music songs without any negative comments about the sound quality or listening experience.