Conformity to ISO 17534-1:2015

Clarifications on the ISO Standard and Identified Issues

It is important to note that the ISO standard provides recommendations rather than regulatory obligations. While it serves as a reference framework, its application is not mandatory from a legal standpoint.

During our analysis, we identified several issues within the standard that hinder a complete and reliable comparison. Notably, we observed inconsistencies between 2D and 3D visualizations, preventing us from achieving a coherent assessment. Additionally, discrepancies exist between the geometric description of the scene and the corresponding acoustic response, raising concerns about the accuracy and reliability of the standard’s methodology.

Furthermore, with respect to favorable rays, our findings indicate a different implementation of CNOSSOS compared to the approach suggested by the standard. This divergence may have implications for the interpretation and reproducibility of results, necessitating further clarification and alignment.

Conformity table

Conform - Do not the deviate more than ±0,1 dB

NLD Conform - Do not the deviate more than ±0,1 dB neglecting lateral diffraction

Test Case	Conform ?	NLD Conform ?	Largest Deviation	Details
TC01	☑	☑	0.00 dB @ 2000 Hz	TC01
TC02	☑	☑	0.07 dB @ 1000 Hz	TC02
TC03	☑	☑	0.05 dB @ 500 Hz	TC03
TC04	☑	☑	0.07 dB @ 1000 Hz	TC04
TC05	☑	☑	0.00 dB @ 1000 Hz	TC05
TC06	☑	☑	0.06 dB @ 500 Hz	TC06
TC07	☑	☑	0.02 dB @ 1000 Hz	TC07
TC08	☑	☑	0.02 dB @ 1000 Hz	TC08
TC09	☑	☑	0.01 dB @ 250 Hz	TC09
TC10	☑	☑	0.02 dB @ 250 Hz	TC10
TC11	☑	☑	0.02 dB @ 125 Hz	TC11
TC12	☑	☑	0.04 dB @ 500 Hz	TC12
TC13	☑	☑	0.01 dB @ 500 Hz	TC13
TC14	☑	☑	0.04 dB @ 8000 Hz	TC14
TC15	☑	☑	0.06 dB @ 250 Hz	TC15
TC16	☑	☑	0.00 dB @ 2000 Hz	TC16
TC17	☑	☑	0.05 dB @ 500 Hz	TC17
TC18	☑	☑	0.02 dB @ 500 Hz	TC18
TC19	□	☑	0.77 dB @ 250 Hz	TC19
TC20	☑	☑	0.00 dB @ 8000 Hz	TC20
TC21	□	☑	0.81 dB @ 63 Hz	TC21
TC22	☑	☑	0.00 dB @ 125 Hz	TC22
TC23	□	□	2.13 dB @ 4000 Hz	TC23
TC24	□	□	1.04 dB @ 2000 Hz	TC24
TC25	☑	☑	0.01 dB @ 2000 Hz	TC25
TC26	□	□	0.47 dB @ 63 Hz	TC26
TC27	□	□	1.76 dB @ 500 Hz	TC27
TC28	□	□	4.99 dB @ 250 Hz	TC28

TC01

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.00 dB	1000
Lꜰ	0.00 dB	500

TC02

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.05 dB	1000
Lꜰ	0.07 dB	1000

TC03

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.08 dB	1000
Lꜰ	0.05 dB	500

TC04

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.06 dB	1000
Lꜰ	0.07 dB	1000

TC05

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.00 dB	1000
Lꜰ	0.00 dB	1000

TC06

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.04 dB	500
Lꜰ	0.07 dB	500

TC07

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.06 dB	1000
Lꜰ	0.00 dB	250

TC08

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.06 dB	1000
Lꜰ	0.01 dB	1000

Right Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.08 dB	2000
Lꜰ	0.06 dB	1000

Left Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.03 dB	1000
Lꜰ	0.04 dB	1000

TC09

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.00 dB	500
Lꜰ	0.00 dB	63

Right Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.03 dB	500
Lꜰ	0.01 dB	125

Left Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.01 dB	250
Lꜰ	0.01 dB	250

TC10

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.00 dB	500
Lꜰ	0.00 dB	500

Right Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.02 dB	125
Lꜰ	0.02 dB	125

Left Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.02 dB	125
Lꜰ	0.02 dB	125

TC11

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.00 dB	4000
Lꜰ	0.00 dB	4000

Right Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.05 dB	250
Lꜰ	0.05 dB	250

Left Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.05 dB	250
Lꜰ	0.05 dB	250

TC12

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.02 dB	250
Lꜰ	0.02 dB	250

Right Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.06 dB	4000
Lꜰ	0.06 dB	4000

Left Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.04 dB	1000
Lꜰ	0.04 dB	1000

TC13

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.01 dB	1000
Lꜰ	0.00 dB	8000

Right Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.01 dB	125
Lꜰ	0.01 dB	125

Left Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.00 dB	125
Lꜰ	0.00 dB	125

TC14

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.04 dB	8000
Lꜰ	0.04 dB	4000

Right Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.06 dB	8000
Lꜰ	0.06 dB	8000

Left Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.08 dB	2000
Lꜰ	0.08 dB	2000

TC15

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.01 dB	125
Lꜰ	0.00 dB	1000

Right Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.24 dB	500
Lꜰ	0.40 dB	250

Left Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.04 dB	8000
Lꜰ	0.04 dB	8000

TC16

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.00 dB	1000
Lꜰ	0.00 dB	1000

Reflection

---

Parameters	Maximum Difference	Frequency
Lʜ	0.00 dB	63
Lꜰ	0.00 dB	4000

TC17

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.04 dB	500
Lꜰ	0.07 dB	500

Reflection

---

Parameters	Maximum Difference	Frequency
Lʜ	0.04 dB	500
Lꜰ	0.03 dB	500

TC18

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.06 dB	500
Lꜰ	0.00 dB	2000

Reflection

---

Parameters	Maximum Difference	Frequency
Lʜ	0.00 dB	250
Lꜰ	0.00 dB	1000

TC19

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.02 dB	63
Lꜰ	0.02 dB	63

Right Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.07 dB	500
Lꜰ	0.01 dB	125

Left Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	6.46 dB	8000
Lꜰ	6.46 dB	8000

TC20

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.00 dB	8000
Lꜰ	0.00 dB	8000

TC21

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.02 dB	125
Lꜰ	0.02 dB	250

Right Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.08 dB	8000
Lꜰ	0.08 dB	8000

Left Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.07 dB	500
Lꜰ	0.33 dB	500

TC22

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.01 dB	4000
Lꜰ	0.00 dB	4000

Right Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.06 dB	500
Lꜰ	0.02 dB	125

Left Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.05 dB	500
Lꜰ	0.01 dB	125

TC23

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.02 dB	250
Lꜰ	3.56 dB	4000

TC24

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.02 dB	250
Lꜰ	0.02 dB	63

Reflection

---

Parameters	Maximum Difference	Frequency
Lʜ	0.02 dB	63
Lꜰ	3.53 dB	4000

TC25

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.00 dB	1000
Lꜰ	0.01 dB	250

Right Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.01 dB	1000
Lꜰ	0.01 dB	1000

Left Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.01 dB	2000
Lꜰ	0.01 dB	2000

Reflection

---

Parameters	Maximum Difference	Frequency
Lʜ	0.00 dB	1000
Lꜰ	0.00 dB	2000

TC26

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.00 dB	4000
Lꜰ	0.06 dB	4000

Reflection

---

Parameters	Maximum Difference	Frequency
Lʜ	0.01 dB	4000
Lꜰ	15.33 dB	8000

TC27

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.02 dB	2000
Lꜰ	0.18 dB	125

TC28

Vertical Plane

---

Parameters	Maximum Difference	Frequency
Lʜ	0.01 dB	63
Lꜰ	7.05 dB	250

Right Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	0.09 dB	2000
Lꜰ	2.09 dB	8000

Left Lateral

---

Parameters	Maximum Difference	Frequency
Lʜ	5.75 dB	8000
Lꜰ	9.57 dB	63