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. Author manuscript; available in PMC: 2015 Nov 6.
Published in final edited form as: J Rehabil Res Dev. 2014;51(1):81–100. doi: 10.1682/JRRD.2013.04.0092

Figure 7.

Figure 7

Maximum permissible ambient noise levels (MPANLs) (in decibels re: 20 μPa, American National Standards Institute S3.1–1999) for audiometric test room is shown as function of frequency when HDA 200 (circles) circumaural earphones and Etymotic ER2 (triangles) earphones are used. Hospital noise (asterisk) levels as function of frequency measured in 1/3-octave frequency bands (Gordon et al., 2005 [45]) are also shown. Data show that reliable behavioral hearing thresholds can be obtained for frequencies above 2,000 Hz in most circumstances. In addition, room noise using OtoID is measured just before presentation of each tone as extra measure that noise levels in room are well controlled. Using insert earphones for collecting distortion-product otoacoustic emissions, all f2 frequencies can be used.