New Apple Audio Patents

This is serendipitous: While searching for information on the history of GarageBand, I entered Acid/GarageBand programmer Chris Moulios’ name and found this intriguing patent application. Called “Method and Apparatus for Expanding Audio Data,” it offers a peek inside the conceptual process of warping audio:

One method relies on crossfading pairs of segments of audio data while running one segment backward every other repetition. The second time stretching method detects inaudible segments and inserts longer periods of audible data within those segments. The third method utilizes a reverb to create a reverb segment that is played after the original segment.

Another Moulios patent deals with changing the tempo of audio during playback. Browsing patent applications in the same category—Electrical audio signal processing systems and devices—gives other glimpses into where digital audio is heading, whereas browsing applications by the Hecker Law Group, which presumably represents Apple, suggests what new audio breakthroughs might be coming out of Infinite Loop. How about:

• Extending the Bandwidth of a Class D Amplifier Circuit
• Evaluating and Correcting Rhythm in Audio Data
• Simulating a Mechanical Keyboard Action in an Electronic Keyboard
• Advanced Manipulation of Audio (an especially interesting one that seems to define a new type of container format that would carry both waveform data and synthesis instructions)

Hooray for the public domain!