SoundStudio Glossary

Glossary of audio terms

Plain definitions of the words used in SoundStudio and in audio work generally. Where a term matches something in the app, the line under it says where to find it. For the ideas behind these terms, read the Audio theory tutorial.

A B C D E F G H I K L M N O P Q R S T U V W Z

A/B compare: Listening to two versions back to back, switching instantly at the same spot, to hear which is better. Fair only when both play at the same loudness, because the louder one nearly always sounds better at first.In SoundStudio: Analyze, A/B Compare (loudness matched).
AAC: A lossy audio format, the usual sound inside .m4a files and most Apple and YouTube audio. At the same bitrate it sounds a little better than MP3.In SoundStudio: Helper tab, Export: M4A (AAC 256 kbps).
AIFF: Apple's uncompressed audio format, the Mac cousin of WAV. Same quality as WAV.In SoundStudio: Opens through the Helper, since most browsers cannot read it.
Aliasing: False tones that appear when a sound contains frequencies above half the sample rate. They fold back down into the audible range and sound harsh or metallic. Good resamplers filter them out first.
Amplitude: How far a waveform swings from the center line. Bigger swings are louder. Measured in dB.In SoundStudio: The height of the waveform on screen.
Attack: On a compressor or limiter: how fast it turns the sound down once the level goes over the threshold. Fast attack catches sharp peaks; slow attack lets the start of each note punch through.In SoundStudio: Dynamics tab.
Audacity labels: A plain text list of times and names that the free editor Audacity imports as a label track (File, Import, Labels).In SoundStudio: Noise tab: Audacity Labels. Helper tab: Save Audacity labels for lyrics.
Autosave: SoundStudio keeps a copy of every open file and your selection in the browser's own storage a few seconds after each change, so a refresh or crash loses nothing.In SoundStudio: Files tab: Autosave session.
Band: A range of frequencies, for example 2 to 4 kHz. EQ bands boost or cut one range.In SoundStudio: EQ tab; Repair range in the click tools.
Bit depth: How many bits describe each sample. 16-bit (CD) gives about 96 dB between the loudest and the quietest possible sound; 24-bit about 144 dB. More bits means a lower noise floor, which matters while editing.In SoundStudio: Export: WAV 16-bit or 24-bit.
Bitrate: How much data per second a compressed file uses, in kbps (kilobits per second). For MP3, 128 kbps is acceptable, 192 good and 320 the best MP3 can do.In SoundStudio: Export: MP3 bitrate.
BPM (tempo): Beats per minute: how fast the music's beat goes. 60 is slow, 120 is a typical pop tempo, 170 is fast.In SoundStudio: Analyze, Track and File and Style.
Bulk Apply: Runs the same steps on every loaded file, one after another.In SoundStudio: Header: Bulk Apply.
Buzz: Hum with many harmonics, so it sounds raspy rather than a pure low tone. Usually a ground loop, a dimmer or a cheap power supply.In SoundStudio: Analyze, Problems: lists each frequency to notch.
Channel: One stream of audio. Mono has one channel, stereo has two: left (L) and right (R).In SoundStudio: Tools tab: Channels.
Chorus: An effect that mixes in slightly delayed, slightly wavering copies of the sound, so one voice or guitar sounds like several.In SoundStudio: Effects tab.
Click: A very short burst, usually under a few milliseconds, that does not belong in the audio. Heard as a tick, click or crackle.In SoundStudio: Noise tab: Click and Pop Removal.
Clipping: What happens when a signal tries to go louder than the maximum a system can store. The tops of the waveform get cut flat, which adds harsh distortion.In SoundStudio: Tools tab: Detect Clipping, Repair Clipping.
Codec: The method that squeezes audio into a smaller file and unpacks it again: MP3, AAC, Opus and FLAC are codecs.
Compression (data): Making a file smaller. Lossless compression (FLAC) keeps every sample; lossy compression (MP3, AAC, Opus) throws away detail you are unlikely to hear.
Compression (dynamics): Automatically turning loud parts down so the difference between loud and quiet shrinks. Makes a voice sit steadier and sound closer. Not the same as file compression.In SoundStudio: Dynamics tab.
Correlation (stereo): How alike the left and right channels are, from +1 (the same, mono) through 0 (unrelated, very wide) to below 0 (opposite, out of phase, parts cancel on a mono speaker).In SoundStudio: Analyze, Track and File.
Crest factor: The gap between a sound's peaks and its average level, in dB. Natural recordings have a large crest factor; heavily compressed masters a small one.
Crossfade: Fading one piece of audio out while the next fades in over the same few milliseconds, so a join has no click.In SoundStudio: Used automatically on every cut, paste and Smooth Cut.
dB (decibel): A ratio on a logarithmic scale. +6 dB doubles the waveform's height, -6 dB halves it, and about +10 dB sounds roughly twice as loud.
dBFS: Decibels relative to full scale. 0 dBFS is the loudest a digital file can hold; everything else is a negative number. -6 dBFS is half of full scale.In SoundStudio: Meters tab; Normalize.
dBTP (true peak): The real peak level between samples, measured by rebuilding the waveform in finer steps. A file can peak at -0.2 dBFS on its samples but go over 0 between them, which clips in players and MP3 conversion. -1 dBTP is the common safe ceiling.In SoundStudio: Enhance tab; loudness normalize.
DC offset: When a waveform is shifted up or down so it is not centered on zero. It wastes headroom and makes cuts click. A high-pass filter removes it.
Declick: Finding clicks and rebuilding the damaged samples from the audio around them.In SoundStudio: Noise tab.
Declip: Rebuilding the flattened tops of clipped peaks.In SoundStudio: Tools tab: Repair Clipping.
DeepFilterNet: An AI noise reducer that keeps voices and removes hiss, hum, room noise and background chatter.In SoundStudio: Helper tab: AI noise reduction.
Delay: An echo effect: a copy of the sound repeated after a set time, often fading with each repeat (feedback).In SoundStudio: Effects tab.
Delivery target: The loudness and peak level a station, platform or client asks for, for example -24 LUFS and -2 dBTP for US TV, or -16 LUFS and -1 dBTP for podcasts.In SoundStudio: Enhance tab, Delivery Check.
Demucs: An AI program from Meta research that splits a mix into vocals, drums, bass and other instruments.In SoundStudio: Helper tab: Separate Stems.
Distortion: Changing a waveform's shape so new harmonics appear. Wanted on an electric guitar; unwanted when it comes from clipping.In SoundStudio: Effects tab.
Dither: A tiny amount of noise added when reducing bit depth (for example 24 to 16-bit) so quiet fades do not turn grainy.
Ducking: Turning one sound down while another plays, most often the music under a voice, then bringing it back up. Done with a fade down before the voice and a fade up after it.In SoundStudio: Tools tab: Volume Pins.
Dynamic range: The distance between the quietest and loudest parts, in dB.
Envelope (volume): The line that shows a track's level over time. Bending it down for a stretch is ducking; bending it up is a boost. Each bend has a ramp in and a ramp out.In SoundStudio: Tools tab, Volume Pins (the orange line on the waveform).
EQ (equalizer): Turning chosen frequency ranges up or down: more bass, less mud, more clarity.In SoundStudio: EQ tab.
Expander / gate: The opposite of a compressor: it turns quiet parts down further. A gate turns them off completely. Used to hush noise between phrases.In SoundStudio: Voice processing, Auto Enhance (Voice).
Fade: A gradual change in volume from silence (fade in) or to silence (fade out).In SoundStudio: Tools tab: Fade In, Fade Out.
FFmpeg: A free command-line program that reads and writes almost every audio and video format.In SoundStudio: Installed with the Helper; used for FLAC, M4A, Opus and opening unusual formats.
FFT: Fast Fourier Transform: the math that turns a slice of waveform into a list of the frequencies it contains. Spectrums and spectrograms are built with it.
Fit to Length: SoundStudio's time compression tool: makes audio exactly the length you type without changing the pitch.In SoundStudio: Effects tab.
FLAC: Free Lossless Audio Codec. A file about half the size of WAV with every sample kept exactly.In SoundStudio: Helper tab: Export FLAC.
Formant: The resonances of the throat and mouth that make a voice sound like that person. Keeping formants when shifting pitch avoids the chipmunk effect.In SoundStudio: Rubber Band pitch shift keeps them.
Frequency: How many times per second a wave repeats, in hertz (Hz). Low numbers are low pitches.
Fundamental: The lowest and usually strongest frequency of a note; it sets the pitch you hear.
Gain: A change in level, usually in dB. +3 dB of gain makes it a little louder.In SoundStudio: Tools tab: Apply Gain.
Harmonics: Frequencies at whole-number multiples of the fundamental (2x, 3x, 4x...). Their mix gives each instrument its tone.
Headroom: Space between the loudest peak and 0 dBFS. Leaving a few dB lets effects and conversions work without clipping.
Hertz (Hz), kHz: Cycles per second. 1 kHz is 1,000 Hz. People hear roughly 20 Hz to 20 kHz; the top end drops with age.
High-pass filter: Lets high frequencies through and removes the lows below a cutoff. Used to remove rumble and DC offset. Also called low cut.In SoundStudio: EQ tab: Low Cut.
Hiss: Steady high-frequency noise, like air or tape noise.In SoundStudio: Noise tab: Remove Hiss; Helper: AI noise reduction.
Hum: A steady low tone from electrical wiring: 60 Hz in North America, 50 Hz in Europe, plus multiples (120, 180 Hz...).In SoundStudio: Noise tab: Remove Hum.
Interpolation: Filling in missing or damaged samples by estimating them from the samples around them.In SoundStudio: Click repair uses LSAR interpolation.
Knee: On a compressor: how gradually it starts working as the level nears the threshold. A soft knee sounds more natural.In SoundStudio: Dynamics tab.
Latency: Delay between an action and hearing its result, usually from audio buffers.
Limiter: A very fast, very strong compressor that stops the level from ever going above a ceiling.In SoundStudio: Dynamics tab.
Loop: Playing a section over and over.In SoundStudio: Transport: loop button.
Lossless / lossy: Lossless formats (WAV, FLAC, AIFF) keep the audio exactly. Lossy formats (MP3, AAC, Opus) discard detail to save space; each re-encode loses a little more.
Loudness: How loud something sounds to people, which depends on frequency and duration, not just peak level.
LRA (loudness range): How much the loudness varies over a program, in LU. A ballad has a larger LRA than a heavily compressed pop song.
LSAR: Least-squares autoregressive interpolation. It learns the pattern of the audio on both sides of a gap and fills the gap with the samples that best continue it. SoundStudio's click and clip repair use it.
LUFS: Loudness Units relative to Full Scale: the standard measure of how loud a whole song or program sounds (ITU BS.1770). Streaming services play music around -14 LUFS; broadcast uses -23 (Europe) or -24 (US).In SoundStudio: Enhance tab; Normalize to Target LUFS; watch folder.
Makeup gain: Gain added after compression to bring the overall level back up.In SoundStudio: Dynamics tab: Gain.
Mastering: The final stage: overall EQ, compression and loudness so a song sounds finished and matches other releases.
Metadata (tags): Text stored inside an audio file: title, artist, album, year, genre, comment. MP3 files use ID3 tags, WAV files use INFO tags.In SoundStudio: Analyze, Metadata. Written into WAV and MP3 exports.
Meter (peak, RMS): A peak meter shows the highest instant level; an RMS meter shows the average power, closer to how loud it sounds.In SoundStudio: Meters tab.
Mix: Several tracks combined into one stereo file. Also the act of setting their levels and effects.In SoundStudio: Files tab: Mix Files Together (play it and set each level while you listen).
Mono / stereo: Mono is one channel, heard the same from every speaker. Stereo is two channels, which allows left-right placement.
MP3: The most widely supported lossy format.In SoundStudio: Export: MP3.
Music bed: Music played under a voice, as in a radio spot or podcast intro. Also called the underscore. It usually sits 12 to 18 dB under the voice.In SoundStudio: Tracks, Mix Files Together, and Volume Pins to duck it under the voice.
Mute and solo: Mute silences one track. Solo plays only the soloed tracks so you can check one part by itself.In SoundStudio: Mix Files Together: M and S buttons.
Noise floor: The level of the quietest background noise in a recording.
Noise profile: A sample of noise alone that the noise reducer studies so it knows what to remove.In SoundStudio: Noise tab: Capture Noise Profile.
Normalize: Changing the whole file's level by one fixed amount. Peak normalize sets the loudest peak to a target; loudness normalize sets the average loudness (LUFS).In SoundStudio: Enhance tab and Tools.
Notch filter: A very narrow cut that removes one frequency completely and leaves the rest alone. The standard fix for mains hum.In SoundStudio: EQ tab: set a band's Type to Notch, or click a peak in the Spectrum tab.
Nyquist frequency: Half the sample rate: the highest frequency a sample rate can hold. 44.1 kHz audio holds up to 22.05 kHz.
Octave: A doubling of frequency. 220 Hz to 440 Hz is one octave; it holds 12 semitones.
Octave bands: The spectrum split into one-octave slices (31.5, 63, 125 Hz... 16 kHz) with the total level in each; a quick check of tonal balance.In SoundStudio: Spectrum tab.
Opus: A modern lossy format that sounds very good at low bitrates; used by WhatsApp, Discord and web calls.In SoundStudio: Helper tab: Export Opus.
Pan: Placing a sound between left and right.In SoundStudio: Effects tab: Pan.
Parametric EQ: An EQ where each band's frequency, gain and width can all be set, instead of fixed sliders at fixed frequencies.In SoundStudio: EQ tab.
Peaking (bell) filter: An EQ band that boosts or cuts around one center frequency, tapering off on both sides like a bell.In SoundStudio: EQ tab: Type Bell.
Phase: Where a wave is within its cycle at a given moment. Two copies out of phase cancel each other.In SoundStudio: Tools tab: Invert Phase.
Pitch: How high or low a note sounds. Mostly set by the fundamental frequency.
Pitch drift: A voice slowly or suddenly sitting higher or lower than it should, for example between takes of a voice ad.In SoundStudio: Pitch tab: phrases in orange; Wave + Pitch view.
Pitch shift: Changing pitch without changing length.In SoundStudio: Effects tab: Pitch Shift.
Pitch tracking: Measuring the pitch of a voice or single instrument moment by moment, drawn as a line over time.In SoundStudio: View menu: Wave + Pitch; Pitch tab.
Playhead: The vertical line that marks the current play position.
Pop: A click that is longer or lower in pitch, often from plosives (p, b), vinyl or a bad edit.
Project: A folder that keeps everything for one job: the audio, numbered saves you can go back to, optional autosaves and a change log.In SoundStudio: Projects tab (left side).
PWA (installed app): Progressive web app: a web page that installs like a program, gets its own window and works offline.In SoundStudio: Files tab: Install as app.
Q: How wide an EQ band is. Low Q is broad and gentle; high Q is narrow and surgical. Q 1 is about 1.4 octaves wide, Q 4 about a third of an octave.In SoundStudio: EQ tab: Width and Q in the band editor, or mouse wheel over a dot.
Ramp and curve: A ramp is the time a level change takes. The curve is its shape: an S-curve starts and ends gently and sounds most natural; a straight ramp changes evenly but its corners can be heard.In SoundStudio: Volume Pins: Ramp in, Ramp out and Curve.
Ratio: On a compressor: how much the level over the threshold is reduced. At 4:1, a sound 8 dB over the threshold comes out only 2 dB over.In SoundStudio: Dynamics tab.
Reference pitch: The pitch a voice should sit at. Phrases are compared with it and can be shifted back to it.In SoundStudio: Pitch tab: Whole file or Use selection.
Release: On a compressor: how fast it lets go after the level drops back under the threshold.In SoundStudio: Dynamics tab.
Resample: Converting audio to a different sample rate. Playing a recording back at a different rate without resampling changes both speed and pitch, like tape.
Resonance (ringing): A narrow frequency that rings louder than its neighbors, from a room, a mic or an object. In a voice it sounds boxy or hollow; a narrow EQ cut tames it.In SoundStudio: Analyze, Problems: Ringing or resonant tones.
Reverb: The wash of reflections a room adds after a sound. Added as an effect to make audio sound like it is in a space.In SoundStudio: Effects tab.
RMS: Root mean square: an average level that tracks perceived loudness better than peaks do.In SoundStudio: Meters tab.
Rubber Band: A professional library for time stretching and pitch shifting, used in many studio programs.In SoundStudio: Fit to Length Engine, with the Helper.
Rumble: Very low energy under about 30 Hz from traffic, handling, wind or a desk bump. You barely hear it, but it uses up headroom and makes compressors pump. A low cut removes it.In SoundStudio: Analyze, Problems; EQ low cut.
Sample: One number describing the waveform's height at one instant. CD audio has 44,100 samples per second per channel.In SoundStudio: Zoom all the way in to see single samples.
Sample rate: How many samples per second: 44.1 kHz (CD, music) or 48 kHz (video, broadcast) are standard.In SoundStudio: Shown next to the file name.
Scan: The old name (before v3.11) for Skip.In SoundStudio: Transport bar: now labeled Skip.
Scrub: Dragging the playhead and hearing the audio under it, faster or slower as you move, like rocking tape across a tape head.In SoundStudio: Transport: Scrub, drag the ruler or playhead, S key.
Selection: The highlighted stretch of audio that edits and effects act on.
Semitone: One step on a piano keyboard; 1/12 of an octave, a frequency ratio of about 1.059.In SoundStudio: Pitch Shift works in semitones.
Shelf filter: An EQ band that raises or lowers everything below (low shelf) or above (high shelf) a frequency by the same amount.In SoundStudio: EQ tab: Type Low shelf or High shelf.
Sibilance: Harsh 's', 'sh' and 't' sounds, mostly between 5 and 8 kHz.
Skip: How far the « and » buttons in the transport bar (and the [ and ] keys) jump back or forward: 1, 5, 10, 30 or 60 seconds per press. At 5s, each press moves the playhead 5 seconds. Handy for moving through a long file while it plays.In SoundStudio: Transport bar: Skip.
Smooth Cut: Cutting out part of a held note and matching the waveform on both sides of the cut so the note stays smooth.In SoundStudio: Tools tab, Shift+Delete.
Spectrogram: A picture of sound with time across, frequency up, and loudness as brightness. Clicks show as thin vertical lines.In SoundStudio: View menu (or V): Spectrogram, or Wave + Spectrogram.
Spectrum: The level of each frequency in a sound, shown as a curve: low frequencies on the left, high on the right.In SoundStudio: Spectrum tab (selection, whole file or live); small version in the Meters tab.
Spike: A single sharp peak that stands out above the waveform around it.In SoundStudio: Spike Pen; Spikes above the outline detector.
Spike Pen: A tool that repairs (or cuts) the spike you click on.In SoundStudio: Noise tab or P key.
Split marker: A marker that divides a long file into separate pieces for export.In SoundStudio: Split tab; Shift+click.
Stem: One separated part of a mix, such as the vocal or the drums.In SoundStudio: Helper tab: Separate Stems.
Stereo width: How wide the stereo image sounds, from mono (0%) to extra wide.In SoundStudio: Effects tab.
Stop (long jobs): The Stop button on the progress bar that appears during long jobs, or the Esc key. Ends the job at its next checkpoint.In SoundStudio: Bottom of the screen while a job runs; Helper tab: Stop jobs on PC.
Suno tick: A tiny broadband click that AI song generators like Suno sometimes leave in their output.In SoundStudio: Noise tab: Detector, Suno ticks.
Threshold: The level where a compressor, limiter, gate or detector starts to act.
Time compression: Radio term for making a spot shorter without changing the pitch, for example a 35 second read into a :30.In SoundStudio: Effects tab: Fit to Length.
Time stretch: Changing length without changing pitch.In SoundStudio: Effects tab: Time Stretch.
Transient: The sharp start of a sound, like a drum hit or a plucked string.
Underscore: Another name for a music bed: music placed under speech or action.In SoundStudio: See Music bed.
Undo history: The list of steps Ctrl+Z can take back. Each open file has its own.
Volume Pins: SoundStudio's tool for shaping a track's volume envelope: marked stretches where the level drops (ducking) or rises (a boost) by a set amount, each with its own ramp in, ramp out and curve.In SoundStudio: Tools tab: Volume Pins.
Watch folder: A folder the Helper keeps an eye on; any song dropped in gets processed automatically.In SoundStudio: Helper tab.
WAV: The standard uncompressed audio file on Windows. Best for editing and archiving.In SoundStudio: Export: WAV.
Waveform: The picture of the audio's level over time.
Whisper: An AI speech recognizer from OpenAI that turns speech and singing into text with timings.In SoundStudio: Helper tab: Lyrics timing.
WSOLA: Waveform similarity overlap-add: a time stretch method that cuts audio into short overlapping pieces and lines each one up with the one before, so the pitch stays the same.In SoundStudio: Fit to Length, Built-in engine.
Zero crossing: A point where the waveform crosses the center line. Cuts made there are less likely to click.
Zoom: How much of the file fills the screen. Zoomed all the way in, you see individual samples.