Unchirp

Codec Artifact Removal & Transient Retrieval

UNCHIRP is a plug-in for removing the most obnoxious artifacts associated with lossy audio encoding and other FFT based processes, such as spectral de-noising. Reduce musical noise, suppress high frequency chirping (also known as underwater sound, warbling or the tweeties), fix transient smearing, and restore lost high frequencies – UNCHIRP does it all in one go. If you need to salvage poorly encoded music, speech that has gone through a low bit rate uplink, material that has been de-noised too strongly, or footage recorded with consumer mobile devices – or if you simply want to add contour and vibrance to already great sounding recordings – UNCHIRP is your (only) friend.

The UNCHIRP features at a glance: 

• Suppression of high frequency "chirping" artifacts.

• Reduction of "musical noise" artifacts.

• Transient Synthesis to augment or replace smeared, over-limited or otherwise compromised transients.

• Psycho-Acoustically optimized Treble Boost circuit with Enhance and Excite modes.

• Break-Point Curve Editor based frequency-dependent processing.

• Side-only algorithm mode for working with joint-stereo encoded material.

• HD algorithm mode for increased quality processing with higher CPU load (off-line processing recommended).

• SYNC parameter allows processing to be synchronized to signal transients for increasing clarity.

• Output limiter for unsupervised use in batch processing applications.

• Highly time-efficient workflow and UI.

The Problem

Both lossy codecs as well as many of today's DSP processes (like de-noisers) make heavy use of a process called the Fast Fourier Transform (FFT). This method has some major advantages. It also has some major drawbacks, which are the root cause for a variety of artifacts, such as Musical Noise, High Frequency Modulation (a.k.a. Chirping), Transient Smearing, and overall "blurring" due to low localization in the time domain. Because of the way human hearing works, these artifacts are very obvious and sound distinctly unnatural. Additionally, lossy codecs and de-noisers often cause a loss of high frequencies, further degrading your audio. UNCHIRP is the medicine for all of these artifact types.