Psychoacoustics

R2026b

Perceptual metrics and sound quality evaluation

Audio Toolbox™ provides features relating to psychoacoustics, which is the study of how humans perceive sound. Use these features to measure perceptual properties of sound, such as loudness, tonality, quality, and intelligibility.

Functions

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Metrics

`integratedLoudness`	Measure integrated loudness and loudness range
`loudnessMeter`	Standard-compliant loudness measurements
`stoi`	Short-time objective intelligibility measure (Since R2024a)
`visqol`	Objective metric for perceived audio quality (Since R2024a)
`speechTransmissionIndex`	Measure channel ability to transmit intelligible speech (Since R2026a)
`speechInterferenceLevel`	Measure speech interference level (SIL) from audio signal (Since R2026b)
`speechIntelligibilityIndex`	Measure speech audibility using speech intelligibility index (SII) metric (Since R2026b)
`acousticToneToNoiseRatio`	Identify and quantify tones in acoustic signals (Since R2023b)
`acousticProminenceRatio`	Quantify tonality by comparing critical bands (Since R2023b)
`acousticLoudness`	Perceived loudness of acoustic signal
`acousticSharpness`	Perceived sharpness of acoustic signal
`acousticFluctuation`	Perceived fluctuation strength of acoustic signal
`acousticRoughness`	Perceived roughness of acoustic signal
`calibrateMicrophone`	Calibration factor for microphone

Domain Conversion

`erb2hz`	Convert from equivalent rectangular bandwidth (ERB) scale to hertz
`bark2hz`	Convert from Bark scale to hertz
`mel2hz`	Convert from mel scale to hertz
`hz2erb`	Convert from hertz to equivalent rectangular bandwidth (ERB) scale
`hz2bark`	Convert from hertz to Bark scale
`hz2mel`	Convert from hertz to mel scale
`phon2sone`	Convert from phon to sone
`sone2phon`	Convert from sone to phon

Blocks

Loudness Meter

Standard-compliant loudness measurements

Topics

Measuring Speech Intelligibility and Perceived Audio Quality with STOI and ViSQOL
Use the STOI and ViSQOL metrics to measure speech intelligibility and perceptual audio quality in speech and audio signals.
Technical Standards Implemented in Audio Toolbox
Technical standards and common industry metrics implemented in Audio Toolbox.

Featured Examples

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Validate ISO 532-1/2 Acoustic Loudness Compliance

Validate the acoustic loudness function in MATLAB.

Since R2026b
Open Live Script

Speech Transmission Index - IEC 60268-16 Edition 5.0 Compliance

Demonstrate compliance using various test signals described in IEC 60268-16 rev. 5 (2020) annex A and C.

Since R2026a
Open Live Script

Effect of Soundproofing on Perceived Noise Levels

Measure engine noise and use psychoacoustic metrics to model its perceived loudness, sharpness, fluctuation strength, roughness, and overall annoyance level.

Open Live Script

Loudness Normalization in Accordance with EBU R 128 Standard

Use tools from Audio Toolbox to measure loudness, loudness range, and true-peak value.

Open Live Script

Psychoacoustic Bass Enhancement for Band-Limited Signals

An audio plugin designed to enhance the perceived sound level in the lower part of the audible spectrum.

Open Live Script

THD+N Measurement with Tone-Tracking

Measure total harmonic distortion and noise level of audio input and output devices.

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