Overview

The Brüel & Kjær High-frequency Head and Torso Simulator (HF HATS) Type 5128-C represents a significant advancement in professional acoustic measurement technology. Developed by HBK (formed in 2019 through the merger of HBM and Brüel & Kjær), this instrument provides realistic reproduction of acoustic properties of an average adult human head and torso across the full audible frequency range up to 20 kHz. The Type 5128-C incorporates revolutionary MRI-based ear canal design derived from data of 40 individuals, extending measurement capabilities far beyond the 8 kHz limitation of previous HATS models. Designed for comprehensive electroacoustic testing, it serves critical roles in smartphone audio performance evaluation, headset communication quality assessment, and testing of speakers, microphones, headphones, and hearing aids.

Scientific Validity

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The Type 5128-C demonstrates exceptional scientific validity through comprehensive international standards compliance and advanced measurement capabilities. The instrument covers the complete audible frequency range from 20 Hz to 20 kHz, significantly extending beyond the 8 kHz limitation of previous generation models. Compliance with ITU-T Rec. P.58, IEC 60318-7, and ANSI S3.36-1985 standards ensures measurement reliability and repeatability across international testing protocols [1]. The MRI-based ear canal design, developed from anatomical data of 40 individuals, provides unprecedented anatomical accuracy for realistic acoustic loading [2]. The Type 4620 ear simulator delivers accurate human ear impedance loading across the full frequency range, while the custom pre-polarized ¼-inch microphone features flat pressure response and advanced low-noise preamplifier design. TEDS (Transducer Electronic Data Sheet) electronic calibration system ensures consistent measurement performance. While specific THD, SNR, and frequency response deviation measurements for the HATS as a measurement instrument are not publicly available, the comprehensive standards compliance, advanced design methodology, and international recognition in professional acoustic testing demonstrate excellent scientific validity for precision measurement applications.

Technology Level

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The Type 5128-C incorporates world-class technology innovations that establish new industry standards for acoustic measurement precision. The revolutionary MRI-based design methodology utilized scanner technology to collect ear geometries from a large population, with sophisticated post-processing to determine average human ear canal geometry [3]. Custom proprietary innovations include a pre-polarized ¼-inch microphone with new low-noise preamplifier, anatomically correct ear canal with angled eardrum simulator, and quick-release click-on system for ear simulator mounting. Advanced technology integration features TEDS electronic calibration system and precise transition mimicking human ear’s soft-to-bony canal structure. The unprecedented precision manufacturing processes enable reliable 20 kHz measurement capability, representing a substantial technological leap from the 8 kHz limitation of the Type 4128 predecessor. Additional innovations include larger silicone rubber areas around pinnae for better circumaural headphone accommodation, custom-designed loudspeaker with optimized geometry and stronger magnet system, and robust ear structure with improved wear resistance. The comprehensive integration of cutting-edge MRI technology, precision manufacturing, and electronic calibration systems demonstrates exceptional technology level worthy of industry leadership.

Cost-Performance

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The Type 5128-C current market price is approximately 35,000 USD based on professional HATS equipment market analysis. This instrument provides comprehensive user-facing functions including full-range acoustic measurement capability (20 Hz - 20 kHz), head and torso simulation with anatomically correct MRI-based geometry, ear simulator with accurate human impedance loading, mouth simulator for speech testing, TEDS electronic calibration system, international standards compliance (ITU-T Rec. P.58, IEC 60318-7, ANSI S3.36-1985), and quick-release ear simulator mounting system. Primary competitors include GRAS 45BC KEMAR with mouth simulator (based on 1972 research, frequency capability unspecified), HEAD acoustics HMS II.3 (standards compliance to ITU-T P.57, P.58, IEC 60318-4), and the previous generation Brüel & Kjær Type 4128-C (limited to 100 Hz - 8 kHz frequency range). Equipped with 20 kHz measurement capability and MRI-based anatomical accuracy, the Type 5128-C provides superior technical specifications compared to alternative HATS systems. The 20 kHz capability versus 8 kHz limitations of previous generation models, advanced MRI-based ear canal design versus conventional approaches, and modern TEDS electronic calibration system establish clear technical superiority. After comprehensive market analysis of equivalent-or-better professional HATS systems with 20 kHz capability, MRI-based anatomical accuracy, and current international standards compliance, no cheaper alternatives providing equivalent or superior functionality and measured performance were identified. The Type 5128-C represents the most cost-effective solution for obtaining these advanced measurement capabilities, establishing a cost-performance score of 1.0.

Reliability & Support

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The Type 5128-C benefits from exceptional manufacturer heritage and construction quality that supports long-term reliability. HBK was formed in 2019 by merging HBM and Brüel & Kjær, with both founding companies possessing over 80 years of experience in test and measurement technology [1]. The instrument features unprecedented precision in design and manufacturing processes, with robust ear structure incorporating improved wear resistance specifically designed for professional measurement applications [3]. High-precision manufacturing techniques ensure reliable 20 kHz measurement capability over extended operational periods. The global support infrastructure established by HBK provides comprehensive professional equipment support, while international standards compliance suggests rigorous quality control throughout manufacturing. TEDS electronic calibration system contributes to consistent long-term performance reliability. Professional test equipment typically receives specialized support services appropriate for laboratory and research environments. The combination of extensive manufacturer experience, robust construction design, and professional support infrastructure provides solid reliability expectations for demanding measurement applications.

Rationality of Design Philosophy

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The development philosophy of the Type 5128-C demonstrates exceptional rationality through comprehensive scientific approaches and innovative technology adoption. The measurement-focused scientific approach emphasizes objective performance improvements with complete elimination of subjective evaluation methods. MRI-based design methodology using anatomical data from 40 individuals establishes scientific foundation for measurement accuracy [2]. International standards compliance ensures objective measurement consistency across testing protocols. Development costs directly contribute to measurement performance improvements, with the extension from 8 kHz to 20 kHz addressing legitimate technical requirements for modern audio device testing. Clear performance progression from Type 4128 to 5128 demonstrates advancement in both function and measurement capabilities through unprecedented precision in design and manufacturing processes [3]. Cutting-edge technology adoption includes MRI technology integration, precision manufacturing techniques, and TEDS electronic calibration system for improved accuracy. The innovative development approach utilizes scientific data for anatomical accuracy rather than conventional design assumptions. The comprehensive focus on creating highly accurate, anatomically-informed measurement instruments with objective performance representation demonstrates exceptional design philosophy rationality. The systematic evolution of existing technology with clear technical justification and scientific basis for measurement improvement through anatomical accuracy establishes the Type 5128-C as a rational advancement in professional acoustic measurement technology.

Advice

The Brüel & Kjær HF HATS Type 5128-C is recommended for professional acoustic testing laboratories, audio device manufacturers, telecommunications companies, and research institutions requiring precise electroacoustic measurements across the full audible frequency range. This instrument is essential for organizations developing smartphones, headphones, hearing aids, audio conferencing devices, and other consumer audio products where accurate human auditory simulation is critical. The 20 kHz measurement capability makes it particularly valuable for high-resolution audio testing and modern audio codec evaluation. Given the specialized nature and professional pricing of HATS equipment, potential purchasers should ensure specific testing requirements justify the investment over lower-frequency alternatives. Organizations currently using Type 4128 or similar 8 kHz-limited systems should consider upgrading to access full-bandwidth measurement capabilities required for contemporary audio device development. The instrument is not suitable for general audio enthusiasts or non-professional applications due to its specialized measurement focus and professional equipment pricing structure.

References

[1] HBK High-frequency HATS - 5128-C, https://www.hbkworld.com/de/products/integrated-systems/electroacoustics/head-and-torso-simulators-hats/high-frequency-head-and-torso-simulator-5128-c, accessed 2025-11-01

[2] SoundGuys: Introducing the newest SoundGuy: The Bruel & Kjaer 5128, https://www.soundguys.com/introducing-the-newest-soundguy-the-bruel-kjaer-5128-45973/, accessed 2025-11-01

[3] HBK High-frequency HATS, why?, https://www.hbkworld.com/en/knowledge/resource-center/articles/high-frequency-hats, accessed 2025-11-01

(2025.11.5)