Auxiliaris

Minimum requirements for noise protection in construction are predominantly determined by single number values. Since construction methods change regularly and noise protection against "new" sources must also be ensured, people's perception of noise must also be examined again and again. These investigations are carried out with so-called subjective listening tests and can lead to new design values and minimum requirements. In this project, first the software and hardware as well as the premises for subjective listening tests will be modified and implemented. Furthermore, listening tests for the assessment of noise events will be conducted and analysed. These results will be compared with results from the partner research institution, National Research Council Canada (NRC).

1. Do Stuttgart residents perceive impact noise from ceilings similarly to Canadian and South Korean citizens?
2. Which outdoor noise sources are most annoying for residents indoors?
3. Can indoor events be used for hearing tests by third-octave filtering of outdoor events?

• Matlab source code from NRC for the impact sound tests is adapted for the German language and existing hardware (headphones / AD/DA converter / computer).
• Listening test system is calibrated and hearing tests are performed and analysed to answer question 1.
• Source code is rewritten to be able to perform listening tests from measured indoor sounds.
• Listening tests are performed and analysed in response to question 2.
• Indoor sounds are generated by third-octave filtering of outdoor sounds.
• Listening tests are carried out and analysed to answer question 3. If the answer to the question is positive, indoor sounds can be simulated by third-octave filtering. This means that the characteristics of the sources and the facades are recorded separately and simply all combinations can be simulated to build a much larger database.

By carrying out and analysing the listening test as part of the measurement campaign, it was possible to confirm that the A-weighted outside level has little significance for the sound pressure level that ultimately prevails in the building and the noise annoyance there. Rather, the excitation spectrum of the traffic noise and the typical sound insulation of double--glazed insulated windows results in a maximum in the interior spectrum around approx. 200 Hz. In addition, hearing tests were carried out with the real measured interior noise levels, which allow further important conclusions to be drawn about the annoyance caused by these noises. Software applications were developed by using the mathematical-scientific software Matlab® and the results to date were presented and discussed at a scientific conference (DAGA 2023) and discussed there.

In addition to the results, this will expand the competence in listening tests at HFT Stuttgart. In this way, even closer cooperation with the research group of business psychologists on the topic of human judgement could be sought.

Furthermore, this competence can be applied to other ongoing projects (noise protection in ground floors, DiaOpt4iCity, SPlanRob) and new projects in which the assessment of sounds is important.

Further details can be found in the final report.