‘So you can distinguish between different buses by their sounds?’ I get asked this question a lot. The answer is: yes!

When I was in primary school, I had no difficulty distinguishing between the sounds of the various bus models: the Leyland Victory Mark 2 had a rough sound; the Daimler Fleetline sounded like the mooing of a cow; the rough Metro Cammell had a direction indicator with a very loud beeping sound. As most routes were served by specific vehicles, I was even able to guess the bus routes based on their sounds. But that was long ago. Since the millennium, with retirement of the non-air-conditioned buses, and introduction of the first generation of white, air-conditioned buses, not only has the appearance but also the sounds of the engines of the new buses become more similar. After all, bus companies have saved maintenance costs by using similar engines for all their bus models, so naturally they all sound alike. To use an analogy, listening to the sounds of buses in the 1990s was like distinguishing between different musical instruments; now it is like distinguishing between the sounds of different brands of piano – which is technically much more difficult.

And I am only human, yet there are those in this world endowed with magical ears.

My friend Max fell in love with buses when he was in primary school year five or six. As with most bus enthusiasts, all love begins with on sight. Max’s favourite was the single-door Dennis Trident. Before its retirement, this model mostly served the Airport–Tung Chung route. ‘I lived in Lam Tin, and the E22 route used to use a single-door Dennis Trident. The bus measured only 11 metres long, but since there was only one front door, it looked very long. I would always ride in one of those.’

This love at first sight only lasted for two years. Since secondary school Max began to lose his eyesight, and most of the activities undertaken by bus enthusiasts, such as appraising the appearance of a bus and the scenery of a bus route, became impossible for him. ‘The last bus I perceived visually was probably a MMC (2012 model). The Facelift (2015 model) already looked rather blurry. It’s a pity that I can’t see, because new models keep coming out, and I can only go to the terminus to feel them with my hands, or get a toy model bus to handle at home.’ Hence his sensual perceptions shifted from sight to touch and hearing, and his focus extended from appearances to the feel of the rolling chassis, engine, machinery, shock absorbers, even the effects of the driver’s driving habits, as well as the various sounds.

One day Max and I were passing by Johnston Road in Wanchai. It was just after rush hour, and the street was still crowded with people and vehicles. Suddenly Max asked, ‘Is that a hair dryer?’ Listening closely, I realised that this E500 MMC (Alexander Dennis Enviro500 MMC) just passing in front of us did sound a bit like a hair dryer. ‘No. 23,’ Max said nonchalantly. Only a magical ear could hear a bus model on the noisy Johnston Road in 2023. Watching Max guessing the bus route was like watching the 1980s TV series The Shell Game, in which ‘Eye of the Southern God’ played by Patrick Tse could tell the digits of the dice by ear after losing his sight. Max often gets it right, despite the many bus routes passing along Johnston Road.

More than that, he can tell a lot about the vehicle’s structure and if there are any problems by the sounds of its parts: The heightening of his other senses has compensated for his loss of sight. Whether the swinging motion, the starting and braking, and the shock absorption of a vehicle are suitable for the Hong Kong roads, the trajectory, the driver’s skills etc., these are perceived through all parts of his body. The pleasure of speed can also be obtained through hearing: ‘Taking the electric City Bus 8910 and then hearing the labouring sound of the Kowloon Motor Bus Enviro500 MMC, first in front of us then as we leave it behind, is really exhilarating.’ Without any cue from other senses, speed itself is experienced merely by the passing sound.

As sound is so important to public transport enthusiasts, it follows that very meticulous documentation must be made. However, it is not easy to record all the sounds of a moving vehicle. Listening for sounds inside a bus or train is like listening inside a musical instrument where sounds are coming from all directions: The engine, announcements, rattling window-panes, the vibrating structure, tyre noises, the squeals of friction on the rails, the collision of carriages… sounds of different levels come from all directions. In addition to that, recording devices and playback tools tend to distort the sounds, making sound documentation difficult. Therefore, professional sound documentation has always been coveted by public transport enthusiasts. Catering especially to this, on the fifth floor of the Shosen Book Tower in Akihabara, Tokyo are shelves lined with hundreds of CDs named after the many Japanese railway routes, containing sound recordings of the various moving trains.

Such sound collections do not only exist in Japan. One can easily find recordings of subway announcements from London and New York on the Internet. The same with Hong Kong: In 2022, bus 301 was to be cancelled due to the extension of the East Rail Line to Admiralty. The excited bus enthusiasts onboard the last bus were talking loudly and shouting until the farewell announcement sounded. All at once everyone fell silent and held up their mobile phones towards the speaker on the ceiling to record the announcement. That also happened with the farewell announcement of the Mid-Life Refurbishment Train. More professional collectors use high-end recording equipment like Boom. Before the retirement of the Light Rail Phase 2 LRV, many train enthusiasts rented it for pleasure rides, and the accommodating train operator activated many special announcements, such as those for a train breakdown, emergency evacuation, temporary route change, etc. Being able to record these rare sounds is undoubtedly satisfying for the enthusiasts.

To make a comprehensive documentation of a vehicle, one must first understand its structure. Many videos on the Internet demonstrate how to document the engine of a sports car: Place the microphones near the rolling chassis, exhaust pipe and engine, then insulate them with sponges… Though one may install any kind of recording equipment in one’s own vehicle, the preparation required for recording a bus is much more complex. So how to properly record the sounds of a moving bus?

According to our expert Max, we should at least set up recording equipment in the front, middle and rear sections of the lower deck of the bus: One on the lower deck in front of the door for the sounds of the direction indicators and the door itself; another at the front and rear of the drive shaft (the second wheel of the bus) for the sounds of the rear axle, where torque produced by different gear ratios and the differential rotational speeds can be captured; then of course at the engine at the rear of the vehicle, which is also the main source of sound. Another important source of sound is the radiator, which in the old buses was located under the stairs, and now mostly lies in the rear of new ones. According to Max, when these all sound together, it is beautiful like a symphony.

Max has compiled at least a hundred bus sound recordings. At the beginning of each, Max notes the bus model, route, licence number, and direction. Listening to the sounds of some of the retired buses that he recorded many years ago—for example, the Dennis Trident that once traversed the whole of Hong Kong, creating an important city soundscape—past events resurface for Max one after the other. We mustn’t forget that the sounds of the buses and railways are songs that many Hong Kong people listen to every day and night.

It’s not only public transport enthusiasts that are sensitive to the sounds of vehicles. My own grandfather, a patriot, used to tell my mother that the train to mainland China sounded like ‘Cin4cing4-Cin4cing4 Cin4cing4-Cin4cing4 (Forward-Forward Forward-Forward)’; while the train back to Hong Kong sounded like ‘Ban6sat6-Ban6sat6-Ban6sat6-Ban6sat6 (Dumb-ass Dumb-ass Dumb-ass Dumb-ass)’…

「你係咪識分辨巴士聲？」——這是我常被問及的問題。答案是可以的。

我在小學時很容易分辨出各種型號：勝利二型（Leyland Victory Mark 2）聲音粗獷；珍寶巴士（Daimler Fleetline）像牛叫；都城嘉慕（Metro Cammell）粗獷之餘，指揮燈的嘟嘟聲非常響亮。很多路線都有特定的用車：所以我還能在熟悉的路段中，用聲音去估路線——但這已是從前的事。千禧年代後，隨著非空調巴士和初代白色冷氣巴士的退役，不只外型，引擎的聲音也催向近似。畢竟巴士公司近年在不同號使用近似的引擎，節省維修成本，機器的聲音自然相近。打個比喻，90 年代聽巴士聲，像分辨不同樂器；現在則是分辨不同廠牌的鋼琴，難度是天壤之別。

我只是凡人，但世界上確是有神耳的。

朋友 Max 從小學五六年級喜歡巴士——和大部份車迷一樣，一切的愛源於視覺。Max最喜歡的，是單門版本的丹尼斯三叉戟 (Dennis Trident)，退役前多數行走機場東涌路線。「我住喺藍田，當年 E22 就係行單門三叉戟。其實部車只係 11 米，但因為得車頭有門，所以睇落好長，我會特登揀部單門坐。」

視覺帶來的愛只是維持了兩年。Max 初中開始漸漸失明，從視覺上欣賞外型、路線風景等一般巴士迷能享受的事也無法繼續。「最後一部視覺上能感受到，應該係 MMC（2012年新車），Facelift版（2015）本已經很模糊。睇唔到係有遺憾，因為不停出新車，只能去總站摸吓，或者買部巴士模型返黎摸。」於是整個感官從視覺轉移到觸覺、聽覺；喜好也從外型內延至感受底盤、引擎、機械、避震；甚至司機駕駛的習慣，以至各種聲音。

有次跟Max出街，經過灣仔莊士敦道——當時剛過繁忙時間，街上仍人多車多。Max 突然問我：「風筒？」乍聽之下，才發現剛在前面經過的這部 E500 MMC（Alexander Dennis Enviro500 MMC）的聲音有點像風筒：「23號」—— Max 淡然說。在 2023 年能在嘈吵的莊士敦道聽出型號，絕對是神耳。看著 Max 在估路線，就像八十年代劇集《千王之王》，「南神眼」謝賢失明後仍能聽骰一樣。莊士敦道路線繁多，Max也常能估中。

他從機件的聲音也可以聽出車的結構與問題——因為失去視力，其他感官都放得很大，汽車的擺動，起動與煞車、避震是否適合香港，行駛的軌跡，司機駕駛技術等，都能從身體各個部份接收。速度的快感，也能從聽覺中得到：「坐電動城巴 8910，聽到前面九巴歐六 MMC (Enviro500 MMC)行得好辛苦，我地一嘢就過，好爽。」不用旁邊的人告知，只憑聲音從前面走到後面，便是速度。

聲音既對交通迷如此重要，也必定對紀錄相當講究。然而，紀錄整全的行車聲音絕不容易——巴士和鐵路內聽聲音，就如置身樂器之中，前後左右都是發生元件：引擎、廣播、玻璃在抖動、結構在震；汽車的胎噪、路軌摩擦聲、車卡接駁位之間的碰撞——聲音四方八面而來，層次不同。加上錄音裝置和播放工具會把聲音失真，聲音紀錄一直不容易。因此，專業的聲音記錄一直是交通迷趨之若鶩的事。東京秋葉原的書泉書店五樓，是特別為交通迷而設的一層，這裏有一個 CD 架， 上面印著數以百計不同的日本鐵路路線名字。CD 的內容是不同路線運行聲音的錄音。

這些聲音收集者不單在日本出現，網上不難找到倫敦、紐約地鐵的廣播聲音。香港也不例外：2022 年，301 巴士因東鐵延長到金鐘而取消，尾班車上的巴士迷本來相當雀躍，高聲談話，大呼小叫。301 巴士告別廣播響起時，所有巴士迷都立刻肅靜，並把電話舉高至天花喇叭位置，把廣播錄起；東鐵綫「烏蠅頭」(Mid-Life Refurbishment Train) 列車告別廣播也不例外。更專業的收集者，會用上 Boom 等專業收音器材——輕鐵第二代列車告別前，不少鐵路迷租用了該輕鐵車輛來遊車河，車長也相當「識做」，按動了不少平常難以聽到的特別廣播，例如列車故障、緊急疏散、臨時更改路線通知等。這些聲音原本是可遇不可求，現在能輕易錄起，當然過癮。

若要全面的紀錄一部車，就必先要了解汽車的結構。網上有不少影片，示範如何紀錄跑車引擎——把首音咪放在底盤、死氣喉、引擎附近；用海棉防風……自己的車當然可以任意安裝收音設備，可是錄巴士的方法，需要準備的事就更多了。如何錄好巴士的行駛聲音？專家 Max 說，起碼要在巴士下層前中後放置收音設備：下層上車門前一個，負責收好打指揮燈和頭閘開門聲音；驅動軸前後（巴士第二個車輪）負責「尾牙」的聲音，可以聽見不同的齒輪比產生不同的扭力，還有轉彎的差速；車的最後當然是引擎，也是整部車最主要的聲音來源。另一個聲音來源則是水箱，舊巴士放在樓梯下方，新巴士多在車尾，也是巴士發聲的重要來源。全部一同響起，Max 的形容是交響樂的美妙。

Max 錄起的巴士聲音，少則百條。每條聲音開始時，皆會講述一次巴士型號、路線，車牌和行車方向。聽他多年前錄起的一些退役巴士聲音——那曾經走遍全港，是街頭重要市聲的丹尼斯三叉戟聲音，幕幕舊事顱內奏起。不要忘記，巴士聲、鐵路聲是很多香港人日常一早一晚聽著的歌。

當然，不是交通迷也會對交通工具的聲音敏感。筆者的外公非常愛國，他當年常跟我媽說，坐火車到中國的聲音，像是「前程前程 前程前程」；回香港的火車聲，則像「笨實笨實 笨實笨實」……

Leyland Victory Mark 2 (Photo by Max Lam)
勝利二型 （Max Lam 攝）

Daimler Fleetline (Photo by Lam Siu Wing)
珍寶巴士 （林兆榮 攝）

Metro Cammell (Photo by Lam Siu Wing)
都城嘉慕 （林兆榮 攝）

Alexander Dennis Enviro500 MMC (Photo by Max Lam)
亞歷山大丹尼士 E500 MMC （Max Lam 攝）

Alexander Dennis Enviro500 MMC Facelift (Photo by Max Lam)
亞歷山大丹尼士 E500 MMC Facelift （Max Lam 攝）