Medium upholstered chair, unoccupied, front side of seat back 2.5 cm, rear side of seat back 0, top of seat bottom 5 cm, arm rests solid, Seattle, Opera House

PTB reference data

Original description

Material properties

No further information available.

Measurement data

Sound absorption

ISO 354 – reverberation chamber

Values per m² of audience area, not per chair or person.

α_w

0.60

Frequency values

α_p nach ISO 11654

f (Hz)	250	500	1k	2k	4k
α_p	0.55	0.50	0.60	0.60	0.60

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Value from the PTB table, not verified

Measured values as a table (1 measurement)

Medium upholstered chair, unoccupied, front side of seat back 2.5 cm, rear side of seat back 0, top of seat bottom 5 cm, arm rests solid, Seattle, Opera House: sound absorption coefficient αs per ISO 354 by frequency and test build-up
Build-up	α_w	250 Hz	500 Hz	1000 Hz	2000 Hz	4000 Hz
Measurement 1	0.60	0.55	0.52	0.60	0.62	0.59

Measured values as a table (1 measurement)

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Last updated: 04/09/2026