Tag Archives: glossary

How do you define success? Our latest effort to educate ACX actors and help them become better audiobook producers is an audio terminology glossary coming soon to the ACX website. But first, we wanted to give blog readers a sneak peek of a few key definitions.

• Artifact:  Undesirable sounds around words, such as random, humming noises and metallic sounding breaths. Artifacts can be added to the original audio from excessive or incorrect noise reduction resulting from technical limitations.
• Decibel (dB):  The standard unit of measurement used to represent sound volume or sound level. In the digital audio world, it is often assumed that when referring to “dB”, it actually refers to decibels relative to full scale (dBFS), where “0dBFS” represents the maximum possible digital level. This means that measurements in the digital audio realm are generally represented in negative values (-).
• Edited Master:  Raw audio (unprocessed) that has gone through the editing/quality control pass (QC pass) stage. This form of audio has not been processed a.k.a. mastered, but has been edited and corrected (QC pass).
• Headroom:  A term related to dynamic range expressed in decibels (dB), as the difference between the typical operating level, and the maximum operating level in an audio system. The maximum output level of a Digital Audible Workstation (DAW) is 0dB, though many DAWs have additional headroom built into the master fader which allows sound to be output between +3dBFS and +6dBFS. At Audible Studios, audiobook recordings are limited to a maximum peak of -3dB in order to leave headroom and avoid clipping (distortion caused by audio peaks exceeding 0dB). This limit allows for 3dB of headroom, leaving room for any surprise peaks that may occur when converting or exporting audiobooks to audible.com.
• Limiter:  A type of compressor with a fast attack and release, and a fixed ratio of 20:1 or greater. The dynamic action effectively prevents the audio signal from rising above the output ceiling setting. See “Brickwall limiting” also.
• Normalize:  The process of increasing all digital samples linearly, by the same amount, in order for the largest original sample to reach a given level, based on a peak or RMs value.

Which audiobook production terms do you think should be included in our glossary?