# acousticSharpness

## Syntax

## Description

specifies a nondefault microphone calibration factor used to compute loudness.`sharpness`

= acousticSharpness(`audioIn`

,`fs`

,`calibrationFactor`

)

computes sharpness using specific loudness.`sharpness`

= acousticSharpness(`specificLoudnessIn`

)

specifies options using one or more `sharpness`

= acousticSharpness(___,`Name,Value`

)`Name,Value`

pair arguments.

**Example: **```
sharpness =
acousticSharpness(audioIn,fs,calibrationFactor,'SoundField','diffuse')
```

returns
sharpness assuming a diffuse sound field.

`acousticSharpness(___,`

with no output arguments plots sharpness relative to time.`TimeVarying`

,true)

## Examples

## Input Arguments

## Output Arguments

## Algorithms

Acoustic sharpness is a measurement derived from acoustic loudness. The acoustic loudness
algorithm is described in [1] and implemented in the
`acousticLoudness`

function. The acoustic sharpness calculation is described in [2]. The algorithm for acoustic
sharpness is outlined as follows.

$$sharpness\text{\hspace{0.17em}}=\text{\hspace{0.17em}}k\text{\hspace{0.17em}}\left(\frac{{\displaystyle \underset{z=0}{\overset{24}{\int}}N\text{'}(z)\text{\hspace{0.17em}}g(z)\text{\hspace{0.17em}}z\text{\hspace{0.17em}}\text{d}z}}{{\displaystyle \underset{z=0}{\overset{24}{\int}}N\text{'}(z)\text{\hspace{0.17em}}\text{d}z}}\right)$$

Where *N*' is the specific loudness in sones/Bark. The
function *g*(*z*) and the scaling factor
*k* depend on the specified `Weighting`

method:

: **'DIN 45692'***k* is
set such that a 1 kHz reference tone results in a 1 acum sharpness measurement, and

$$\begin{array}{lll}g(z)=1\hfill & \text{for}\hfill & z\le 15.8\text{\hspace{0.17em}}\text{Bark}\hfill \\ g(z)=0.15{e}^{0.42(z-15.8)}+0.85\hfill & \text{for}\hfill & z>15.8\text{}\text{\hspace{0.17em}}\text{Bark}\hfill \end{array}$$

: **'von Bismark'***k* is
set to `0.11`

, and

$$\begin{array}{lll}g(z)=1\hfill & \text{for}\hfill & z\le 15\text{\hspace{0.17em}}\text{Bark}\hfill \\ g(z)=0.2{e}^{0.308(z-15)}+0.8\hfill & \text{for}\hfill & z>15\text{}\text{\hspace{0.17em}}\text{Bark}\hfill \end{array}$$

: **'Aures'***k* is set
to `0.11`

, and

$$\begin{array}{l}g(z)=0.078\left(\frac{{e}^{0.171z}}{z}\right)\left(\frac{N}{\mathrm{ln}(0.05N+1)}\right)\\ \text{where}\\ N={\displaystyle \underset{z=0}{\overset{24}{\int}}N\text{'}(z)\text{\hspace{0.17em}}\text{d}z}\end{array}$$

## References

[1] ISO 532-1:2017(E). "Acoustics –
Methods for calculating loudness – Part 1: Zwicker method." *International
Organization for Standardization*.

[2] DIN 45692:2009. "Measurement
Technique for the Simulation of the Auditory Sensation of Sharpness." *German
Institute for Standardization*.

## Extended Capabilities

## Version History

**Introduced in R2020a**