Fletcher Mark D, Lloyd Jones Sian, White Paul R, Dolder Craig N, Lineton Benjamin, Leighton Timothy G
Faculty of Engineering and Physical Sciences, University of Southampton, University Road, Southampton, SO17 1BJ, United Kingdom.
Department of Audiology and Hearing Therapy, Royal South Hants Hospital, Brinton's Terrace, Southampton SO14 0YG, United Kingdom.
J Acoust Soc Am. 2018 Oct;144(4):2554. doi: 10.1121/1.5063817.
Recent work showing the presence of a new generation of ultrasound (US) sources in public places has reopened the debate about whether there are adverse effects of US on humans, and has identified weaknesses in standards and exposure guidelines. Systems that rely on very high-frequency sound (VHFS) and US include public-address voice-alarm (PAVA) systems (whose operational status is often monitored using tones at ∼20 kHz) and pest deterrents. In this study, sound pressure levels (SPLs) produced by 16 sources that were either publically available or installed in busy public spaces were measured. These sources were identified through a citizen science project, wherein members of the public were asked to provide smartphone recordings of VHFS/US sources. With measurements made in realistic listening positions, pest deterrents were found that produced levels of up to 100 dB SPL at ∼20 kHz, and a hand dryer was found to produce 84 dB SPL at 40 kHz. PAVA systems were found to emit lower levels of up to 76 dB SPL at ∼20 kHz. Pest deterrents measured breach recommended safe listening limits for public exposure for people who are nearby even for relatively short periods.
最近的研究表明，公共场所出现了新一代超声（US）源，这再次引发了关于超声是否对人类有不良影响的争论，并指出了标准和暴露指南中的不足之处。依赖甚高频声音（VHFS）和超声的系统包括公共广播语音警报（PAVA）系统（其运行状态通常使用约20kHz的音调进行监测）和害虫驱避器。在本研究中，测量了16个公开可用或安装在繁忙公共场所的声源产生的声压级（SPL）。这些声源是通过一个公民科学项目确定的，该项目要求公众提供VHFS/US声源的智能手机录音。在实际聆听位置进行测量时，发现害虫驱避器在约20kHz时产生的声压级高达100dB SPL，发现一台干手器在40kHz时产生84dB SPL。发现PAVA系统在约20kHz时发出的声压级较低，最高可达76dB SPL。测量的害虫驱避器超过了为附近人群推荐的公共暴露安全聆听限值，即使是相对较短的时间。
