In parallel to the ultrasonic noise assessment procedures and research activity in the field there have appeared several papers in the domain of so called high-frequency audiometry which covers the range of frequencies 8-20 kHz. They are important for recognizing the harmfulness and hazard of the audible high frequency sound components in the same range as the one of the low frequency ultrasonic noise. On the other hand there exists a certain inconsequent situation in the general approach to the problem of ultrasonic noise hazard assessment in work places environment which concerns the convention to include the frequency range of 10-20 kHz to the domain of ultrasonics. The range consists of one third octave bands of central frequencies: 10, 12.5, 16, 20 kHz and conventionally is called low frequency ultrasonic noise though at least the components of the two lowest bands are naturally audible by a majority of population (mainly young people).The paper presents a discussion related to some achievements of the two domains and some conclusions which could be useful for a more consequent description of the subject and could be taken into account in the future regulations for the ultrasonic noise assessment in work places environment.

Noise induced hearing loss (NIHL) as one of the major avoidable occupational related health issues has been studied for decades. To assess NIHL, the excitation pattern (EP) has been considered as one of the mechanisms to estimate the movements of the basilar membrane (BM) in the cochlea. In this study, two auditory filters, dual resonance nonlinear (DRNL) filter and rounded-exponential (ROEX) filter are applied to create two EPs, the velocity EP and the loudness EP respectively. Two noise hazard metrics are proposed based on two proposed EPs to evaluate hazardous levels caused by different types of noise. Moreover Gaussian noise and tone signals are simulated to evaluate performances of the proposed EPs and the noise metrics. The results show that both EPs can reflect the responses of the BM to different types of noise. For Gaussian noise there is a frequency shift between the velocity EP and the loudness EP. The results suggest that both EPs can be used for assessment of NIHL.

The Environmental Noise Directive (END), published in 2002, was transposed into Romanian local law in 2005, and it was the starting point for the first urban noise mapping exercises, initially conducted in nine Romanian cities. This paper presents the main evolutionary aspects of the noise assessment process, the development of strategic noise maps, and action plans, dealing with both the legislative side and the practical approach and results obtained. The study considers the specific regulations established by the European Commission regarding environmental noise assessment and deals with the global context at the country level, in which they have been implemented and applied.