scope:

This Technical Report (TR) recommends methods for measuring, reporting and verifying the noise emission of telecommunications equipment operated in a telecommunications network facility. The details of the methods are found in ISO 7779 and ISO 9296. The descriptor used to quantify acoustic noise emission is sound power level in units of bels. Measurements should be performed on each equipment type or model.

The recommendations contained herein apply only to the airborne acoustic noise generated by equipment during normal operation. That is, the document does not apply when the equipment is being serviced. Also, the document does not apply to equipment features which produce sound as an intentional aspect of their operation, e.g. alarm signals, attention signals and so on.