High-frequency HATS Type 5128 standardised for testing telecom devices

Head and Torso Simulator (HATS) Type 5128 has been authorised by the ITU-T (International Telecommunication Union – Telecommunication Standardisation Sector) and ensures makers of products such as mobile phones, headsets (including ear buds that include a microphone) and in-vehicle infotainment systems that provide hands-free communication capabilities, that their goods are also in line with official standards.

These tests – specified by regional, national, and global standards – are defined by organisations such as 3GPP, IEC and IEEE, and they all refer to P.58 for the authorised equipment to be used in the testing required before products are sold for use, and are typically performed both by vendors of communication devices and network providers.

What makes Type 5128 unique is that it is the first and only device to accurately measure over the full human audio frequency range. All previous devices are based on an acoustic coupler design referred to as the ‘type 711 coupler’ (from the original standard IEC 711, now IEC 60318-4), which is only qualified for frequencies up to 8 kHz. With the advent of super-wideband and fullband standards, which define responses to 14 kHz and 20 kHz respectively, the market was struggling to be able to evaluate their products with the approved devices.

“We were concerned that customers were attempting to make measurements on their products using 711-based ear simulators in a frequency range where the acoustic impedance was not defined. It led to a lot of uncertainty in the market,” said Lars Birger Nielsen, Telecom-Audio Market Manager at HBK. “There was clearly a disconnect between the market needs and the approved standards.”

The need for a wider definition of the correct acoustic impedance for the human ear was obvious, but it required extensive research (more than ten years) to be able to accurately define an average acoustic impedance to 20 kHz. That goal has been reached with the ear simulator of Type 5128 HATS and is now defined in the P.57 standard.

“We believe that this is a great breakthrough for the industry to be finally able to measure communication devices over the full human audio bandwidth. We’re all increasingly relying on remote communication in our daily lives, both for business and pleasure, so ensuring optimum audio reproduction can only help with that,” said Thomas Rosenkilde Anderson, CSO for HBK.

“We’re proud that the major investment we’ve made in research in this area has resulted in products that can help many of our customers achieve their product quality.”