Are your South-African audiometer calibrations valid?

Was your audiometer calibrated by an institution that conforms to SANS 17025?

Firstly let’s sort out perception from fact.


What is a “perception”?

The subjective ability to see, hear or become aware of something through the senses.


What is a “fact”? 

A thing that is known to be consistent with objective reality and can be proven to be true with evidence.


Most importantly, what are the facts regarding SANS 10083?

The “facts” in our minds are so often only subjective perceptions. For instance, we might think that our audiometry equipment is calibrated to the SABS standard because we are told it is, but is this really true? Is my perception a fact? Does my equipment comply with the requirements of the Occupational Health and Safety Act? Will disability claims stand up in a court of law? Here are the facts:

Your calibration institution should implement a Quality Management System, in accordance with SANS 17025 to calibrate an audiometer to the SANS standards. Without this certification, a calibration laboratory cannot claim they calibrated the audiometer to the SANS standards. This is a requirement of SANS 10083 (clause 16.3 b) and is regulatory as per the Occupational Health and Safety Act. (See references at the end of this blog)

How do you ensure your calibration institution complies to clause 16.3 b of SANS 10083?

  1. Ask your audiometer calibration institution for their ISO 9001, ISO 13485 or similar QMS certificate.
  2. Ask your audiometer calibration organisation for their Declaration of Conformity stating that they have implemented SANS 17025 for calibrations.

An audiometer calibration laboratory does not need to be SANAS accredited. Nowhere is that a requirement.

The Department of Labour does not certify calibration companies. They can, however, request for this evidence to be provided during an audit.

Surprisingly the above facts might objectify your perceptions. You may find that some organisations that claim to calibrate to SABS standards do not. They did not implement SANS 17025.

“Perceptions are not facts.”

“Here is the evidence that eMoyo complies to these facts:
eMoyo ISO 13485 QMS certificate
KUDUwave Declaration of Conformity to ISO 17025 for calibrations

SANS and Quarterly calibrations

The following few paragraphs may save you thousands, if not tens of thousands of rands every month, so it’s really worth a careful read.

So far the differences between our perceptions and the actual facts regarding who is allowed to calibrate audiometers, as per SANS 10083 have been highlighted. There are many misperceptions around the calibration standards in South Africa, some of which your colleagues may be practising and incurring unnecessary costs. Nowhere in any standard, act or circular instruction (i.e. 171) is there a requirement to calibrate your audiometer every time you move it. Portable audiometers such as the KUDUwave™, or other mobile units, transported from the original site of calibration by road, rail or air, need to be calibrated at least every three months, on condition that certain processes are followed by the operator. 

South African National Standard (SANS) 10154-1 requires that a stationary audiometer that does not leave the location where it was originally calibrated, must be calibrated annually. A mobile audiometer, however, must be calibrated every 3 months. As soon as an audiometer leaves the original site of calibration, it is classified as a mobile audiometer, so it is important to ensure that your audiometer is calibrated every 3 months. This warrants repeating: There is no need to calibrate a digital portable audiometer every time it is moved. See Requirement A.3 below.

It is important to highlight a glaring omission and interpretation of terms in SANS 10154-1. The standard only mentions mobile units and not portable devices. There is a distinct difference in these two terms, especially with regards to medical devices and audiometers in particular. As referenced in IEC 60601-1, The General requirements for basic safety and essential performance, the term Mobile is defined as, “a term referring to TRANSPORTABLE equipment intended to be moved from one location to another while supported by its own wheels or equivalent means”. Portable is defined as, “a term referring to TRANSPORTABLE equipment intended to be moved from one location to another while being carried by one or more persons”. This definitively highlights why a digital portable audiometer such as the KUDUwave, does not need to be calibrated every 3 months but only on an annual basis. However, it’s a tough argument with the legislators and officials and we recommend to play safe and to calibrate your audiometer every 3 months.

Calibration Verification and X-check

Remember to verify the calibration of your audiometer every time you move it by performing a biological calibration check. Alternatively, and this is preferable, if you have X-check built into your KUDUwave you can perform an electroacoustic calibration check, in a matter of seconds to check if your audiometer calibration is still within 5dB of its original calibration. You could also perform a lengthy and subjective biological calibration check, to verify whether your audiometer is still within 10dB accuracy as the standard requires.

If your KUDUwave remains on-site for most of the time, does this mean that quarterly calibrations are no longer required? Well, that depends on a few criteria, namely if your KUDUwave was calibrated in Johannesburg at the eMoyo calibration laboratory and shipped to you, certain parties may deem that the audiometer is a “mobile audiometer”, even though the definition of mobile equipment is transportable equipment intended to be moved from one location to another while supported by its own wheels or equivalent means. The KUDUwave is portable and not mobile. We do however recommend playing it safe and to calibrate the KUDUwave every three months if used as a portable audiometer. Whilst we at eMoyo agree that this is ludicrous, however, unfortunately, this requirement in the standard is not clear, and open to interpretation. Furthermore, we understand that this requirement arose out of the need to periodically re-calibrate analogue audiometers that are reliant on analogue connectors and cables, and subsequently, are at a greater risk of going out of calibration, than digital portable audiometers, such as the KUDUwave that has no analogue cables.

Perception or fact?

The facts say the KUDUwave is one of the few audiometers in occupational healthcare that is calibrated to the SANS standard. Will your calibration certificate by a company that is not ISO 17025, stand up to a query in a court of law?

Ultima verba

Audiometer calibration companies have to conform to ISO 17025. That is what SANS 10083 states. To be ISO 17025 you have to implement an accredited QMS (Quality Management System) like ISO 13485 (that includes traceability) or ISO 9001 with an additional SOP for traceability. These regulatory compliance requirements are stipulated in SANS 10083. ISO 17025 do, however, specify its own QMS at the end of the standard. If you are not ISO 9001 or ISO 13485 then you have to implement the QMS as stipulated in ISO 17025. It is basically a scaled-down version of ISO 13485 like eMoyo has or an upscaled version of ISO 9001. If the company follows the route of implementing the QMS of ISO 17025 it makes sense to use SANAS to accredit their ISO 17025 conformance.



16.3 The calibrating laboratory/organization, where relevant, should

  1. a) prove traceability in accordance with the relevant national legislation (see foreword); Amdt 1
  2. b) implement and maintain a quality management system in accordance with SANS 17025; and Amdt 1
  3. c) issue a calibration certificate of compliance that contains at least the information required in 6.3 of SANS 10154-1:2012. Amdt 1
SANS 10083 ISO17025 required

SANS 17025/ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories. Amdt 1

SANS 10083 ISO17025 required