In the old days zoologists used to identify the different calls of birds, amphibians and insects by the sounds they produced. Even nowadays, catalogues of birds continue to use phonetics to present the unique song of different species for birdwatchers’ easy reference. Through the sounds of nature, we can hear the communications and habits of animals while at the same time, collect information about their habitats. To someone like me who grew up in a farming village, the sounds of nature remind us of the change of seasons. My grandmother loved to say, “When cicadas sing, lychees are ripe.” Indeed, once we heard the singing of cicadas we knew the lychee tree behind our house was ready for harvest. Summer would then follow. The sudden call of frogs during summer was a reminder for us to switch off the light in order to prevent winged ants from flying into the house and causing damages to our wooden furniture. When frogs’ calling is gradually replaced by the sounds of crickets, it is time to get the winter clothes ready.

It seems, however, that these sounds are gradually disappearing. We used to be able to distinguish the different species of birds outside our house by their songs at dawn when they were about to forage around the field and wood. Nowadays we can hardly sleep through the night without being disturbed by constant traffic noise. Sound diversity in Hong Kong has been narrowing along with the decline in size of our farmland. Figures from the Agriculture, Fisheries and Conservation Department show that there were 13,396 hectares of farmland in Hong Kong in 1967 when my grandmother was working on the farm to raise my father. According to the latest government’s consultation document “New Agricultural Policy: Sustainable Agricultural Development in Hong Kong” published in 2014, farmland has been reduced to only 4,523 hectares in 2013. Within this amount of land nearly 3,794 hectares are fallow, of which 968 hectares are owned by the biggest four developers in Hong Kong, namely Henderson Land Development, Sun Hung Kai Properties, Cheung Kong Holdings and New World Development. At the same time, many landowners have changed the land use from farming to car parking and warehousing without official authorization. Reduction in farmland is one of the symptoms of a society that skews towards urban development. This failure to think in terms of sustainable development causes multifold imbalances in our society and is undoubtedly related to the erosion of diversity of sound.

Moving beyond my personal experience, we could look at those controversial mega infrastructure projects like the proposed third airport runway and the development projects in Hong Kong’s western waters, and see how they affect the ecology in those areas. At the top of the food chain inhabiting the western waters of Hong Kong, Chinese white dolphins continue to decline in number within their major local habitats (northwest, northeast and west of Lantau Island), dropping from 158 individuals in 2003 to only around 62 in 2013. This more than halfing of its quantity is directly related to the construction of the Hong Kong–Zhuhai–Macau Bridge. As World Wildlife Fund (WWF) points out, since dolphins rely on echolocation for hunting and communcation, the noises produced by underwater construction such as percusssive piling and increasing marine traffic may interfer with the dophins’ capability to hunt and locate their peers, leading to the loss of such capability and in injuries or death from being hit by vessels.

Constructions of the planned Northern Link and Tuen Mun South Extension also affect marshes reserve in Mai Po and Deep Bay, as ground-breaking works would destroy and pollute the habitats of the migrating birds, and construction noises would interfere with their mating. While we must seriously consider how to reduce the disturbance to the reserve and the area nearby, understanding of the relation between sound and environment in Hong Kong remains within the so-called “people-oriented” approach. That is, we only classify sound that is over 70db as noise, and we only concern ourselves about its health effects on the human auditory sence. Legislative standards are set up accordingly. On the other hand, there have been people complaining to estate management about frogs singing outside their flats in the summer, leading to a ridiculous episode in which security guards were requested to catch frogs. In another incident, spotlights were used to scare and drive away singing cuckoos during their mating season so people could have some good night’s sleep. The world we live in is also the habitats of other living creatures. If we think the sounds made by animals are annoying, consider how heavy traffic overnight on highways next to hills and woods interfere with hunting activities of nocturnal animals like bats and owls! While the above incidents sound absurd, I believe they are the consequence of human being being alienated from nature.

Since R. Murray Schafer’s study of soundscape from the 1970s, artists have been working from the sonic perspective to explore the relationship between living creatures and the environment. Schafer initiated World Soundscape Project (WPS) which developed in 1993 into the World Forum of Acoustic Ecology. This event uses publication and forum to raise awareness in issues related to sound pollution and the ever-changing urban and natural soundscapes. Referencing WPS’s Five Village Soundscapes project from 1975 for their new project, another research organization Acoustic Environments in Change revisited the five European villages between 2002 and 2004 and examined the changes of village soundscape due to urbanization in the past 30 years. The two interviewees in this feature, artist Yannick Dauby and acoustic ecologist Gordon Hempton, also use sound as a starting point and demonstrate two possible relationships between human and nature.
Dayby proposes understanding ecology via sound recording while the Hempton promotes maintaining silence as a starting point for conservation.

Having grown up in southern France, Yannick Dauby uses the sound from his field recordings in Taiwan as a key to unlock its unique ecology and to understand its local traditions. Through the memories from two generations of frogs singing and through identifying the discrepancies between them, he reveals the story of a species evolving in that specific region as well as the changes in its objective environment. During our interview, Dauby said, “Field recording is an activity to activate things.” Through his recordings, he leads the listeners onto a journey of discovery and lets them share the sounds among their own generations. He encourages us to learn from the sounds of now instead of safekeeping them for the future.

Gordon Hempton inaugurated the project “One Square Inch of Silence” after suffering from an ailment. To him, “silence is not the absence of something but the presence of everything.” His work began from conserving a square inch of land from noise pollution, He has since extended his project to protect the soundscape of an entire national park. Hempton encourages us to listen to the richness in the soundscape of silence as a search for self-awakening. “Find a stone, place it somewhere, anywhere; make it your personal ‘One Square Inch of Silence’,” he suggests. He believes that only after we have listened to real silence could we recognize its importance, and consequently, it drives us to find ways to protect it. Using the experiences of the two interviewees as exemplars, we might be able to rethink current environmental issues in Hong Kong with a new perspective. May be we could examine the changes in the environment through our auditory senses, pursue their root causes and reflect on our responses. With regard to Hong Kong’s environmental issues, let’s begin from listening quietly, reflecting attentively, getting involved, and reconnecting with nature.

很久之前，博物學家以聲音辨認不同鳥類、兩棲類及鳴蟲。甚至現時的雀鳥圖鑑，亦會以拼音方式紀錄每個雀鳥的獨特嗚叫，讓觀鳥者參考。在自然的聲音中，我們不僅聽到動物之間的溝通及習性，還有牠們的棲地的資訊。對於在農村長大的我來說，自然的聲音提醒了我們四季的更迭。記得祖母最愛說「蟬鳴荔熟」，聽到蟬鳴你便知道屋後的荔枝樹可以準備採收了，初夏亦隨之到來；夏日晚上突然出現的蛙鳴，提醒我們將會有飛蟻出現，要關好燈防止牠們飛進屋內，以免牠們駐蝕木製家具。蛙聲漸逝，聽到蟋蟀及螽蟴等鳴蟲的聲音時，便知道要把冬天的衣服準備好了。

但這些聲音彷彿漸漸消失，以前在黎明前，可以聽到不同品種的鳥兒在窗外嗚叫，層次分明，準備於田野及林間覓食，但現在聽到的卻是一整夜的車聲，此起彼落， 令人難以入睡。香港的聲音多樣性，與香港的農地面積一樣正逐漸下降，據漁農自然護理處的數字，1967年當祖母以耕作養大父親的時候，香港仍有13,396公頃的農地，但於2014年的《新農業政策：本港農業的可持續發展》諮詢文件中的數字顯示，在2013年農地銳減至4523公頃，其中有近3794公頃列作荒廢農地，而四大發展商（恆基、新地、長實及新世界）便合共持有968公頃的農地。同時不少田地持有人，把農地擅自改作停車場及倉庫，從而申請改變土地用途。農地驟減，是社會一面倒的發展的其中一個徵狀，亦是失去了永續發展的思考，導致社會的多樣性失衡的結果，而這與聲音逐漸變得單一不無關係。

由自我經歷再放遠一點，近日鬧得熱哄哄的的機場第三跑道，以及已開始的發展西海域計劃，海上的大型基建如何影響香港西海域的生境？作為西海域食物鏈頂層物種的中華白海豚，牠們的數量不斷下降。白海豚在三個主要棲息的海域(大嶼山西北、東北及西面)，出沒數量由2003年的158條降至2013年的約62條，下降逾半，這與2009年動工的港珠澳大橋工程有直接關係。世界自然基金會指出撞擊式打樁的海底工程及愈催繁忙的海上交通等發出的噪音，會令以回聲定位來覓食及溝通的白海豚難以接收回音，導致捕獵困難及干擾同類間的交流，甚至因此令白海豚失去自我定位，被船隻撞傷至死。

計劃興建的北環線及屯門南延線，對米埔及后海灣的濕地保護區帶來影響，動工時隨了破壞或污染候鳥的棲地外，工程發出巨大的聲響亦干擾了侯鳥交配。如何減低計畫對保護區及附近保育地帶的影響，是我們需慎重思考的議題。可是在香港，對於聲音及環境的關係，仍停留在「以人為本」的方針，超過70分貝就是噪音，且只是針對聲量大少影響聽覺健康作為厘定法例的指標。近年竟有人因夏天屋外的蛙鳴向屋苑管理處投訴，令保安人員捉青蛙的鬧劇於香港發生，亦有人嫌噪鵑於交配期的鳴叫擾人清夢，以射燈驅趕。我們的生活空間，其實也是其他生物的棲息地，如我們覺得動物的聲音煩擾時，反過來想，建於樹林或山嶺旁的高速公路，於凌晨時份仍有車輛頻繁使用，影響夜行性動物如蝙蝠及貓頭鷹捕食，這些例子除令人感到荒謬外，於我來看，更是人與自然疏離的結果。

其實自70年代由R. Murray Schafer開始，藝術家便以聲音角度出發，探討生物與環境的關係，由他發起的WSP(World Soundscape Project），於1993年發展為 “World Forum of Acoustic Ecology”，透過出版及研討會關注噪音污染問題及不斷轉變的城市及自然聲境。芬蘭研究組織 “Acoustic Environments in Change”，更以WSP於1975年的 “Five Village Soundscapes” 計劃為藍本，在2002至2004年間重新到訪當年錄音的五條歐洲村落，以當地聲境的變化探討近30年來城市化對村落的影響。今次專題中訪問的聲音藝術家澎葉生及聲音生態學家戈登‧漢普頓，同樣以聲音作為起點，展示人與自然關係中的兩種可能－從錄音認識生態環境，以寧靜作為保育起點。

於南法長大的澎葉生，於一段段田野錄音中，以聲音作為線索打開台灣獨特生態的大門，同時亦以錄音認識當地傳統。透過兩代人對蛙鳴的記憶，說出一個物種於某地演變的故事，以聲音記憶的落差，表現出客觀環境的轉變。澎葉生於訪問中說:「田野錄音是把東西活化過來。」他以錄音讓聽者發現事物，與同一代人分享他的田野錄音，提醒我們在當下的聲音中學習，而不是為未來作聲音紀錄。

漢普頓因一次患病的經歷，發起了「一平方寸的寂靜」運動。對他來說，寂靜不是某些事物的消失，卻是萬物的存在。他以保育一平方寸土地不受噪音污染，推展至保護整個國家公園的原生聲景，再進一步於聆聽寧靜中的豐饒聲景，找尋自我的醒覺。漢普頓建議我們:「找一塊石頭，把它放在某處，或任何一處，把它當作你自己的一平方吋的寂靜。」聆聽過真正的寧靜後才會明白其重要性，才可身體力行找到保護他的方法。我想透過兩位受訪者的經驗作為借鏡，為我們思考當下環境議題時，有一個新的角度－以聆聽發現環境中的轉變，然後找尋背後原因及作出回應。靜心聆聽、細心思考，在香港的環保議題上，我們由聆聽作起點，進一步參與其中，再次認識自然。