High-frequency Head and Torso Simulator (HATS) Type 5128 family, with built-in realistic ear and mouth simulators, provide a realistic reproduction of the acoustic properties of an average adult human head and torso. High-frequency HATS is designed for in situ electroacoustics tests and can cover the full audible frequency range (up to 20 kHz). Testing of smartphone audio performance in relation to national and international standards for communication quality. This includes testing of mobile and wireless handsetsEvaluation of the intelligibility of headset two-way communication in the presence of background noise and conditions that may produce feedback into the systemEvaluation of speech intelligibility in two-way communication using hands-free devices such as conference phones and smart speakers based on accurate production of human speech for the evaluation of directivity, intelligibility, feedback and background noise suppressionFacilitates the evaluation of microphone recording accuracy for human speech with variations in level, directivity and sibilanceMeasurement of the audio response of headphones in exactly the way a human would perceive the quality. This allows designers to identify and correct anomalies in headphone design that lead to artefacts in the frequency response. The new ear canal design provides the most benefits to designers of in-ear headphones, where the geometric fit is crucial to the evaluationSound quality evaluation of hearing aids with correct anatomical positioning Measurement of the attenuation and effective sealing of hearing protectors with the correct ear canal geometry and head anatomy Core HF HATS Type 5128-C comes in several variants and is available without ears or mouth for simpler applications.The head and torso geometry of Type 5128-C complies with ITU-T Rec. P.58, IEC 60318-7 and ANSI S3.36-1985. Includes Handset Positioner Type 4606. The handset positioner enables a smartphone to be precisely positioned on the HATS. This results in easier test set-ups and better data quality from electroacoustic tests.The head and torso geometry of Type 5128-D complies with ITU-T Rec. P.58, IEC 60318-7 and ANSI S3.36-1985. Tabletop HATS is a torso-less head that is supported on a foot. Suitable for testing all types of headphones, 5128-B can be used free standing on a desk, fitted on a tripod or on a turntable using a tripod mounting adapter. Tabletop HATS is configurable and includes two ear simulators.Support foot UA-2180 is available as an optional accessory for HF HATS Types 5128-C and -D.The head geometry of Type 5128-B complies with ITU-T Rec. P.58, IEC 60318-7 and ANSI S3.36-1985.