title: Subjective and objective rating of spectrally different pseudorandom noises--implications for speech masking design.
abstract: Artificial sound masking is increasingly used in open-plan offices to improve speech privacy and to reduce distraction caused by speech sounds. Most of the masking sounds are based on pseudorandom continuous noise filtered to a specific spectrum that should be optimized in respect with speech masking efficiency and comfort. The aim of this study was to increase basic understanding regarding the comfort. The second aim was to determine how well objective rating methods (15 different noise indices) predict the subjective ratings. Twenty-three subjects rated the loudness, disturbance, pleasantness, and six other subjective measures of 11 spectrally different noises in laboratory conditions. Speech was not present during the experiment. All sounds were presented at 42 dB LAeq within 50-10,000 Hz. Unexpectedly, the subjects were most satisfied with sounds having emphasis on low frequencies. A sound having a slope of -7 dB per octave increment resulted in the highest satisfaction. Changes in subjective ratings were reasonably well predicted by five noise indices, while many well-known noise indices frequently used in building design underperformed in this task. The results are expected to benefit in the design of masking sounds and other appliances.
authors: Finnish Institute of Occupational Health, Lemminkäisenkatu 14-18 B, 20520 Turku, Finland.
authors: Valtteri
authors: V
authors: Hongisto
authors: Finnish Institute of Occupational Health, Lemminkäisenkatu 14-18 B, 20520 Turku, Finland.
authors: David
authors: D
authors: Oliva
authors: Finnish Institute of Occupational Health, Lemminkäisenkatu 14-18 B, 20520 Turku, Finland.
authors: Laura
authors: L
authors: Rekola
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000162:Acoustics; D000328:Adult; D000368:Aged; D001299:Audiometry; D004644:Emotions; D004777:Environment; D005160:Facility Design and Construction; D005260:Female; D006801:Humans; D007508:Irritable Mood; D008144:Loudness Perception; D008297:Male; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects*; D010470:Perceptual Masking; D057181:Pleasure; D013018:Sound Spectrography; D013067:Speech Perception