The Sottek Hearing Model provides a comprehensive framework for understanding the
nuances of sound perception, including such aspects as loudness, tonality,
roughness, fluctuation strength, sharpness, and impulsiveness. The principal
model was first published more than three decades ago as part of a doctoral
thesis. Over the past few decades, the model has been refined and recently
standardized in the international standard ECMA 418-2. This standard addresses
several psychoacoustic parameters, including a new approach to time-varying
loudness based on a nonlinear combination of partial tonal and noise loudness
(as part of the tonality). This is the preferable approach because the loudness
of tonal components (i.e., tonal loudness) may have a more pronounced impact on
loudness perception than the loudness caused by other components (i.e., noise
loudness). Other standardized parameters include psychoacoustic modulation
analyses. These are roughness, which is employed to evaluate rapidly modulated
sounds (standardized in ECMA 418-2 since 2020, updated in 2024), and fluctuation
strength, which is an adapted model for slowly modulated sounds (planned for
standardization in June 2025). Many practical applications in the automotive
sector require order-related results to be displayed. This is challenging when
considering the coarse frequency estimate typically provided due to the critical
bandwidth of the auditory filters. This resolution is sufficient for
psychoacoustic parameter evaluation but not as an input to an order analysis.
Improvements have recently been made to the Sottek Hearing Model Tonality to
provide results with a very high frequency resolution that allows for accurate
order analysis. The paper describes the method and presents several automotive
application examples.
