title: Is it necessary to penalize impulsive noise +5 dB due to higher risk of hearing damage?
abstract: It is studied whether the +5 dB penalty for impulsiveness established by ISO 1999:1990 accounts for a higher risk of noise-induced hearing loss. A total of 16 normal-hearing human subjects were exposed for 10 min to two types of binaural industrial-recordings: (1) a continuous broad-band noise normalized to L(EX,8 h)=80 dBA and (2) the combination of the previous stimulus with an impulsive noise normalized to L(EX,8 h)=75+5(db penalty)=80 dBA (peak level 117 dBC and repetition rate of 0.5 impacts per second). Distortion product otoacoustic emissions (DPOAEs) were measured in a broad frequency range before and in the following 90 min after the exposure. The group results show that the continuous exposure had a bigger impact on DPOAE levels, with a maximum DPOAE shift of approximately 5 dB in the frequency range of 2-3.15 kHz during the first 10 min of the recovery. No evident DPOAE shift is seen for the impulsive + continuous stimulus. The results indicate that the penalty overestimated the effects on DPOAE levels and support the concept that the risk of hearing loss from low-level impulses may be predicted on an equal-energy basis.
authors.affiliation: Acoustics, Department of Electronic Systems, Aalborg University, Fredrik Bajers Vej 7-B5, DK-9220 Aalborg, Denmark. m.a.arandadetoro@gmail.com
authors.forename: Miguel Angel Aranda
authors.initials: MA
authors.lastname: de Toro
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Ordoñez
authors.forename: Karen
authors.initials: K
authors.lastname: Reuter
authors.forename: Dorte
authors.initials: D
authors.lastname: Hammershøi
mesh_terms: D000158:Acoustic Impedance Tests; D000161:Acoustic Stimulation; D000328:Adult; D000704:Analysis of Variance; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold; D003718:Denmark; D004784:Environmental Monitoring / Q000331:legislation & jurisprudence; D005260:Female; D006291:Health Policy; D006317:Hearing Loss, Noise-Induced / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D009623:Noise, Occupational / Q000009:adverse effects* / Q000331:legislation & jurisprudence; D016272:Occupational Health / Q000331:legislation & jurisprudence; D017084:Otoacoustic Emissions, Spontaneous; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D012815:Signal Processing, Computer-Assisted; D013018:Sound Spectrography; D013997:Time Factors; D055815:Young Adult