Improving the evaluation of soundscape variability via blind source separation

Presented in 174th Meeting of the Acoustical Society of America @ New Orleans, USA

Improving the evaluation of soundscape variability via blind source separation

Tzu-Hao Lin, Yu Tsao
Research Center for Information Technology Innovation, Academia Sinica

Tomonari Akamatsu
National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency

Mao-Ning Tuanmu, Joe Chun-Chia Huang
Biodiversity Research Center, Academia Sinica

Chiou-Ju Yao
National Museum of Natural Science

Shih-Hua Fang
Department of Electrical Engineering, Yuan Ze University

Abstract

Evaluation of soundscape variability is essential for acoustic-based biodiversity monitoring. To study biodiversity change, many researchers tried to quantify the complexity of biological sound. However, the analysis of biological sound remains difficult because the soundscape is made up of multiple sound sources. To facilitate the acoustic analysis, we have applied non-negative matrix factorization (NMF) to separate different sound sources in an unsupervised manner. NMF is a self-learning algorithm which factorizes a non-negative matrix as a basis matrix and an encoding matrix. Based on the periodicity information learned from the encoding matrix, biological chorus and the other noise sources can be efficiently separated. Besides, vocalizations of different species can also be separated by using the encoding information learned from multiple layers of NMF and convolutive NMF. In this presentation, we will demonstrate the application of NMF-based blind source separation in the analysis of long-duration field recordings. Our preliminary results suggest that NMF-based blind source separation can effectively recognize biological and non-biological sounds without any learning database. It can also accurately differentiate different vocalizing animals and improve acoustic-based biodiversity monitoring in a noisy environment.

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以國際技術指引探討我離岸風場水下噪音監測評估適用方法

論文發表於2017台灣風能協會會員大會暨學術研討會與科技部成果發表會

以國際技術指引探討我離岸風場水下噪音監測評估適用方法

湛翔智、蕭婷宇、潘柔安
知洋科技有限公司

連永順、王珮蓉、胡芳瑜
工業技術研究院

林子皓
中央研究院

我國政府採「先示範、次潛力、後區塊」三階段離岸風電推動策略,示範獎勵辦法在2012年公告,評選出3案離岸示範風場,接著於2015年公告潛力場址,目前有超過20件開發案提出申請,首先均需通過環評審查。然而各項環評審查項目中,風場開發產生水下噪音對海洋動物影響的問題較為複雜,主要原因是水下噪音監測方法尚無國際標準,困難處是要在海上取得足夠且有效數據,必須有詳實規劃和充分準備,才能利用測量資料來分析水下噪音影響程度。歐洲離岸風電有超過10個國家投入開發,但各國有不同的水下噪音影響評估方式,其中以德國政府提出的技術指引,在監測要求與開發限制上較為嚴格。而歐盟自2008年提出「良好環境狀態(GES)」綱要,提供給歐盟成員國作為管制參考依據,包含離岸風能開發的監測與評估要求。美國投入離岸風能的前期研究多年,直到2016年完成首座風場正式商轉,同年也公告「海洋哺乳類動物聽覺技術指引」,將水下噪音對數種鯨豚的各種影響程度,制訂出水下噪音傷害管制門檻。本研究將探討國際上最新的水下噪音監測與評估技術指引,並依循國內離岸風場的發展情況,提出適用方式的建議供各界參考。

The government devised the offshore wind promotion strategy with 3 phases, which include Demonstration Incentive Program, Zone Application for Planning, and Zonal Development. The demonstration incentive program was announced in 2012, and three projects have been selected accordingly. Then, the Directions of Zone Application for Planning (DZAP) was announced in 2015. More than 20 projects have applied for the DZAP, and they are required to pass environmental impact assessments (EIA) to obtain the first step approval for construction. However, the impact of underwater noise on marine mammal during construction and operation phases are very complex. The key issue is that the underwater noise monitoring method has no international standards and it is difficult to measure sufficient and valid data at sea. Moreover, EIA needs very detailed planning and comprehensive preparation to obtain data and analyze the impact assessment from underwater noise. More than 10 countries in Europe already installed offshore wind farms and employ different assessment methods for underwater noise impact. The requirement of the German government’s technical guidelines for underwater noise monitoring and assessment is most rigid and strict. Since 2008, the EU has proposed the “Good Environmental State (GES)” framework for the member states to achieve requirements for the offshore wind energy development monitoring and evaluation. The United States announced the Marine Mammal Acoustic Technical Guidance in 2016, which provides several acoustic thresholds on different species of marine mammal. This study will discuss the latest international technical guidelines for underwater noise monitoring and assessment. Finally, we carried out the report included the applicable method of underwater noise monitoring and assessment based on the development of offshore wind farms in Taiwan.

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