Audio restoration
From Wikipedia, the free encyclopedia
Audio restoration is a generalized term for the process of removing imperfections (such as hiss, crackle, noise, and buzz) from sound recordings. Audio restoration can be performed directly on the recording medium (for example, washing a gramophone record with a cleansing solution), or on a digital representation of the recording using a computer (such as a AIFF or WAV file). Record restoration is a particular form of audio restoration that seeks to repair the sound of damaged records.
Modern audio restoration techniques are usually performed by digitizing an audio source from analog media, such as lacquer recordings, optical sources and magnetic tape. Once in the digital realm, recordings can be restored and cleaned up using digital audio workstations. DAW's can perform various automated techniques to remove anomalies using algorithms to accomplish broadband de-noising, de-crackle and de-hiss tasks. Often audio engineers and sound editors use DAW's to manually remove "pops and ticks" from recordings. DAW's are capable of removing the smallest of anomalies without leaving artifacts and other evidence of their removal. Audio restoration is often a time consuming process that requires skilled audio engineers with specific experience in music and film recording techniques.
[edit] Overview
The majority of audio restoration done today is done for music sound recordings and soundtracks for motion picture and television programs. The demand for restored audio has been fueled by new media consumer technologies such as CD and DVD. Modern audio reproduction systems require that sound sources be in the best condition possible to enhance the listening experience. Media content owners have come to recognize the importance of having clean sound on their products to enhance the commercial value of their media assets.
The byproduct of these restoration efforts is that many audio sources are brought into the digital world and preserved for future use. An unfortunate fact is that most of the sound recordings and motion picture soundtracks created over the past century have been lost due to improper storage and neglect.
Enhancements are often done to motion picture soundtracks. For example taking a mono or stereo soundtrack and re-mixing it to a modern 5.1 surround soundtrack. When sources from original discrete audio "stems" containing dialog, music and sound effects are used and properly restored, the enhancements can be significant and highly effective.
[edit] Issues
Audio restoration is a subjective process, and there are many strategies or perspectives that the audio engineer or sound editor can employ. The archival perspective says that audio restoration should restore the recording to its original condition, while the commercial perspective says that the recording should be both restored and enhanced to appeal most immediately with modern audiences.
