For our February 2014 issue, we cover recent patents granted in the area of audio signal processing. The last time we had considered IP in this broad area was in April 2012. Below, we consider several more recent inventions for audio applications as diverse as audio over mobile, digital fingerprinting, spatially enhanced sound, and error concealment in audio coding. Number: US 8,639,501 Title: Method and arrangement for enhancing spatial audio signals Inventors: E. Karlsson, S. de Bachtin Issued: January 28, 2014 Assignee: Telefonaktiebolaget LM Ericsson (Publ) (Stockholm, Sweden) Number: US 8,639,300 Title: Method and apparatus for maintaining transmit audio in a half duplex system Inventors: H. Tan, T. Ooi, K. Teh and H. Yow Issued: January 28, 2014 Assignee: Motorola Solutions, Inc. (Schaumburg, IL) Number: US 8,630,861 Title: Mixed lossless audio compression Inventors: W. -G. Chen, C. He Issued: January 14, 2014 Assignee: Microsoft Corporation (Redmond, WA) Number: US 8,630,848 Title: Audio signal transient detection Inventors: Y. You Issued: January 14, 2014 Assignee: Digital Rise Technology Co., Ltd. (Guangzhou, China) Number: US 8,634,946 Title: Apparatus and method for calculating a fingerprint of an audio signal, apparatus and method for synchronizing and apparatus and method for characterizing a test audio signal Inventors: S. Scharrer, W. Fiesel, M. Neusinger Issued: January 21, 2014 Assignee: Fraunhofer-Gesellschaft zur Foerderung der Angewandten Forschung E.V. (Munich, Germany) Number: US 8,620,644 Title: Encoder-assisted frame loss concealment techniques for audio coding Inventors: S. Ryu, E. Choy and S. Gupta Issued: December 31, 2013 Assignee: QUALCOMM Incorporated (San Diego, CA) Number: US 8,619,998 Title: Spatial audio enhancement processing method and apparatus Inventors: M. Walsh, J. M. Jot, E. Stein Issued: December 31, 2013 Assignee: Creative Technology Ltd (Singapore) Number: US 8,618,402 Title: Musical harmony generation from polyphonic audio signals Inventors: G. Rutledge, W. Campbell, and P. Lupini Issued: December 31, 2013 Assignee: Harman International Industries Canada Limited (Victoria, B.C., Canada) Number: US 8,615,391 Title: Method and apparatus to extract important spectral component from audio signal and low bit-rate audio signal coding and/or decoding method and apparatus using the same Inventors: J. Kim, E. Oh, K.Osipov, and B. Kudryashov Issued: December 24, 2013 Assignee: Samsung Electronics Co., Ltd. (Suwon-si, Korea) Number: US 8,615,095 Title: Automatic volume control for audio signals Inventors: J. -H. Chen Issued: December 24, 2013 Assignee: Broadcom Corporation (Irvine, CA)   If you have an interesting patent to share when we next feature patents related to audio signal processing, or if you are especially interested in a signal processing research field that you would want to be highlighted in this section, please send email to Shantanu Rane (rane AT merl DOT com).