News

e-mail: mailto:sales@otocube.com

TELEPHONE: + 31(0)182-353310

P.O. BOX 120
4930 AC  GEERTRUIDENBERG
THE NETHERLANDS

Facebook: www.facebook.com/otocubenl
Twitter:  @otocubenl

Acoustic insulation

The OtoCube is intended only for supra-liminal audio logical testing

The acoustic insulation of the box has been optimized within the set limits of weight, size and cost price.

The norms can be deduced from ISO8253-3 2009 §4.3:

“Signal-to-noise ratio. The level of any inherent background noise on the recording shall be at least 40dB below the level of the calibration signal...” and further from §7: “Ambient SPL in test room. The ambient SPL’s in the test room shall not mask the speech signals… Requirements for ambient noise during speech audiometry are less stringent than those for pure tone threshold audiometry. If a test room is appropriate for pure tone threshold audiometry down to a certain hearing level value,.., the room can also serve for speech audiometry …down to the same hearing level values ”.

The test situation must comply with the maximum permissible level for ambient noise described in ISO 8253-2 2009 Table II.

The sound insulation of the OtoCube has been optimized for ambient noise like in a normal household situation. As reference, Dutch Applied Scientific Research Organisation TNO has developed a weighting spectrum for household situations (Report: TPD-HAG-RPT-90-0154). The average sound pressure is 55 - 65 dB SPL.

Average household weighing factors

In addition to ISO 8253-2 2009 part 2 the ‘professional version’ of the test box should also comply with the test conditions described in ANSI S3.1-1991.