Head and torso simulator (HATS for short), with the help of which audio tests are performed

Acoustic Testing

Acoustic testing and measurements for hearing aids, emergency call systems and Amazon Alexa

For many years, testing audio equipment with acoustic measurements was part of approval measurements for cell phones. Over the past few years, the field of application for these tests has expanded. Audio tests are now also required as part of the approval of voice or emergency call assistance systems.

All accreditations
All accreditations
Hearing aid

Conducting acoustic testing

We are accredited for testing audio equipment devices and their respective voice quality. Within the scope of our services, we specialize, among other things, in testing the acoustic quality assessment of mobile devices. Depending on the requirements, the acoustic tests are performed with test headphones or the so-called “HATS” (head and torso simulators) as well as professional microphones and audio sources. In addition, we test the operationality and quality of the speech functions of head units and emergency call assistance systems in vehicles for the automotive industry – with the help of specially designed measurement equipment.

Electroacoustic tests on hearing aids

cetecom advanced specializes in particular in performing electroacoustic tests on hearing aids. The recently completely modernized laboratories have fully and partially sound-absorbing chambers, audiological measurement rooms and an audiological measurement stand, each equipped with professional measurement analyzers, microphones and audio sources. The portfolio of acoustic measurements of cetecom advanced advanced includes the services mentioned below.

Electroacoustic testing and EMC testing of hearing aids

  • IEC/EN 60118-0 ed. 3.0
  • NSH 7th edition (Nordic Requirements)
  • NSH 7.0 Annex A
  • IEC 60118-0 ed. 2.0 + am1 ed. 2.0
  • IEC 60118-1 ed. 3.1
  • IEC 60118-2 ed. 2.0 + am1 ed. 2.0 + am2 ed. 2.0
  • IEC 60118-6 ed. 2.0
  • IEC 60118-7 ed. 2.0
  • IEC 60118-13 ed. 4.0
  • IEC 60118-13 ed. 3.0
  • ANSI C63.19 clause 6

Voice quality tests

  • AS/CA S004

Acoustic measurements

  • ETSI EG 202518
  • UL 60950 -1 Annex NAD
  • IEC/EN 62368-1 clause 10.6
  • IEC/EN 60950-1 Am. 12 clause Z.x
  • EN 50332-1
  • EN 50332-2

Sound power measurements

  • ISO 3744
  • ISO 3745
Hand pressing a car emergency button

Emergency call assistance systems

For some years now, the use of emergency call assistance systems in vehicles of various classes has been mandatory in many countries and regions of the world (including eCall, ERA-GLONASS).

We test the operationality and quality of the voice functions of head units and emergency call assistance systems in vehicles for the automotive industry. These tests are usually the basis for the market approval of the emergency call systems.

Information on eCall certification

Information on ERA-GLONASS certification

Logo of the Amazon voice service Amazon Alexa, whose devices must pass the Amazon Alexa Self-Test

Amazon Alexa

When using Alexa, Amazon’s cloud-based voice service, customers expect a high-quality and consistent experience on all Alexa built-in devices. To support this experience, Amazon has implemented a mandated testing process for device manufacturers looking to launch products with the Alexa Built-in Badge.

We support manufacturers of products with the Amazon Alexa feature by adopting the official self-test services.

More Information on the Amazon Alexa Certification

cetecom advanced Audio Lab

Our audio laboratories

We perform acoustic testing in our laboratories in Essen, Saarbrücken and Milpitas (Silicon Valley). Thanks to technically excellent equipment, we can test a wide range of devices.

Accreditations in detail


German Accreditation Body (DAkkS)

Our laboratories in Saarbrücken and Essen are accredited by DAkkS according to DIN ISO 17025 to perform various audio equipment tests.

Detailed information about the scope of accreditation for our audio laboratories in Germany can be found on our accreditation overview.



Our laboratories are accredited by A2LA according to DIN ISO 17025 to perform various audio equipment tests.

Detailed information about our accreditation scope for our audio laboratories in Germany can be found in our accreditation overview.

Expertise acoustic testing

What are the measures of acoustic testing?

  • Sound velocity
    It tells us how fast the sound propagates in a medium. The speed of sound depends on temperature – at room temperature (20 degrees Celsius), for example, it is 343 meters per second.
  • Sound power
    It describes the total sound energy emitted by a sound source per unit of time.
  • Sound intensity
    The technical term stands for the sound power that passes through a sound absorbing surface per unit area.
  • Sound pressure level
    The sound pressure level is a ratio, formed from the reference sound pressure (hearing threshold) and the instantaneous sound pressure.
  • Sound power level
    It describes the noise generated by a product under operating conditions, for example.
  • Averaging level
    Because the sound pressure level is not constant for many sound processes, but varies over time, they are often combined into a single value: the temporal average or average level.
  • Rating level
    It can be used to consider subjective assessments of different types of noise pollution. For this purpose, the average level for the assessment period is often used. In addition, there may be surcharges for impulsiveness, tone and rest periods. The rating level is used, for example, for comparison with the immission guide values.

Which measuring methods are used for audio equipment testing?

The following three methods are used in audio equipment testing: the enveloping surface method, the reverberation chamber method and the comparative sound source method.

  • Enveloping surface method
    This is the most frequently used procedure, because I usually apply it directly at the location of the machines and devices to be tested. It involves measuring the sound power emitted by a noise source by measuring at numerous points on an imaginary enveloping or measuring surface that encloses the source.
  • Reverberation chamber method
    The basis for this method is the fact that the sound power radiated into the room by a noise source must be as great as that absorbed by the room’s boundary surfaces. Thus the sound power can be determined from the absorbed sound energy, calculated from the average sound pressure level of the room and its sound absorption capacity.
  • Comparison sound source method
    In it the sound power is determined by comparing the noise source to be investigated with a reference sound source. For this purpose, the sound pressure levels of both sound sources are recorded at several measuring points and averaged. In practice, this method is rarely used – the basic prerequisite is that a reference sound source and its exact sound power are known.

Are you interested in more details on acoustic testing / audio equipment testing or are you looking for answers to urgent questions? Please contact us. Benefit from our expert support for all challenges regarding the market approval of your products.

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