Optimized reference spectrum for rating the façade sound insulation.

Area of Science:

• Acoustics
• Psychoacoustics
• Building Science

Background:

• Objective sound insulation metrics (SNQs) should reflect subjective annoyance to traffic noise.
• Current ISO 717-7 reference spectra lack psychoacoustic validation.
• Existing SNQs may not accurately represent perceived annoyance from façade-transmitted sound.

Purpose of the Study:

• Develop optimized reference spectra for façade sound insulation.
• Create new SNQs that better correlate with subjective annoyance to road traffic noise.
• Improve the accuracy of acoustic assessments for building façades.

Main Methods:

• Utilized psychoacoustic experiment data including annoyance ratings for various traffic sounds and façade attenuations.
• Employed mathematical optimization to derive new reference spectra for each traffic sound type.
• Assessed the performance of new SNQs using nested cross-validation.

Main Results:

• Optimized reference spectra yielded SNQs that better explained subjective annoyance for 2 out of 5 road traffic spectra.
• Improved performance was also observed for an aggregate of the five road traffic sound types.
• The developed SNQs demonstrated enhanced correlation with perceived annoyance compared to existing metrics.

Conclusions:

• Optimized reference spectra offer a more accurate basis for calculating façade sound insulation SNQs.
• The findings support the development of improved standardized SNQs for better acoustic design.
• This research contributes to aligning objective acoustic measurements with human perception of noise annoyance.