Music Glossary: Audio Theory and Acoustics category

Standardized filters for SPL measurement approximating human sensitivity (A), mid-level (C), or flat (Z). more

Conversion of acoustic energy to heat inside porous/viscoelastic materials; reduces reflections. more

Opposition to acoustic flow; mismatch between media/surfaces causes reflection/transmission. more

Undesired mirrored frequencies caused by sampling content above Nyquist; sounds like inharmonic tones. more

Magnitude of pressure deviation from ambient; correlates to perceived loudness but not linearly. more

Low-pass filter applied before A/D to remove content above Nyquist and prevent aliasing. more

Axial involve one dimension; tangential two; oblique three—each with decreasing strength. more

Psychoacoustic frequency scale dividing the spectrum into 24 critical bands. more

Low-frequency absorber (porous, panel, or resonant) targeting modal peaks/nulls. more

Headphone playback technique using HRTFs/ear-recordings to recreate 3D spatial cues. more

Number of bits per sample determining quantization steps and theoretical dynamic range (6.02 dB/bit). more

Peaked/notched response from summing a signal with a delayed version (reflections or dual mics). more

Reverb created by convolving audio with a measured or synthesized impulse response. more

Ratio between peak and RMS level; higher values indicate more transient material. more

Frequency bandwidths of the auditory system where masking interactions are strongest; basis for Bark/ERB scales. more

Distance where direct and reverberant sound fields are equal in level; beyond it, clarity drops. more

Logarithmic unit expressing ratios of power or pressure. For pressure, dB ∝ 20·log10(P/P₀). more

Mechanical separation to reduce structure-borne transmission (resilient channels, clips, isolation mounts). more

Scattering of reflections over time/space to reduce coloration while maintaining liveliness. more

Low-level noise intentionally added before bit-depth reduction to decorrelate quantization errors. more

Difference between the noise floor and maximum level (noise-limited or headroom-limited). more

First discrete bounces arriving after the direct sound; dominate apparent source width and clarity. more

Phon/sone curves mapping SPL needed at different frequencies for equal perceived loudness (Fletcher–Munson/ISO 226). more

Equivalent Rectangular Bandwidth model describing auditory filter widths across frequency. more

Modified RT60 formula better matching rooms with higher absorption. more

Unintended sound transmission routes (structure, vents, gaps) bypassing main partitions. more

Floor system isolated by elastomeric mounts or layers to limit structure-borne noise. more