Audio processing algorithms (cont.)
Audio can also be improved by virtualization (also known as 3D) algorithms, which enhance the audio played through speakers or headphones by creating an immersive listening experience. Virtualization algorithms increase the size of the audio field and are able to effectively create virtual surround sound even from small portable devices. They analyze the differences and commonalities of the content played through two channels of a stereo system and enhance them to make the user believe that sound is coming from all directions. These algorithms exploit the so-called head related transfer function (HRTF) that explains how sounds interact with and are interpreted by the human head, ear and brain system.
Additional algorithms focus on improving compressed audio. In this case, they strive to recover information that was lost during compression. They typically act on high frequency content (in the order of kHz) and increase clarity. This way high-frequency sounds, like rain in a movie or a guitar solo in a song, will be reproduced in the way they were meant to be heard.
There are many audio converters (ADCs, CODECs and DACs) that support advanced audio processing capabilities. At TI, these algorithms run on an audio digital signal processors (DSP) (or miniDSP), which is integrated into the audio converter. The miniDSP is programmed by using a graphical development environment called PurePath™ Studio. The TLV320AIC36 is just one of the devices in the family that can be used for handsets because of its analog inputs and outputs.
In summary, being able to reproduce high-quality audio in handsets is a complex task that requires the work of a cross-functional design team. Fortunately, electrical engineers now have the right tools: audio processing algorithms, such as the ones presented here.
Download datasheets or order samples and evaluation modules (EVMs) here: www.ti.com/audioprocessing-ca.
For more information on audio converters and to see how they can improve your audio, please visit: www.ti.com/audio-ca.
About the author:
Luca Cacioli is the Portable Audio Marketing Manager at Texas Instruments. He received his BSEE/MSEE from Universita' di Firenze, Florence, Italy, and his MBA from Southern Methodist University (SMU), Dallas, Texas. Luca enjoys soccer and traveling. He can be reached at email@example.com.