Though we might think of film as an essentially visual experience, we really cannot afford to underestimate the importance of film sound. A meaningful sound track is often as complicated as the image on the screen, and is ultimately just as much the responsibility of the director. The entire sound track consists of three essential ingredients: the human voice, sound effects and music. These three tracks must be mixed and balanced so as to produce the necessary emphases which in turn create desired effects. Topics which essentially refer to the three previously mentioned tracks are discussed below. They include dialogue, synchronous and asynchronous sound effects, and music.

虽然我们也许会将电影视为在本质上以视觉为核心的体验，但我们着实不能低估了电影声音的重要作用。一套内涵丰富的电影原声常常和银幕上的画面同样复杂深刻，并且最终也是影片导演需要肩负的重要职责。完整的原声包括三个核心组成元素：演员说话声、音效和音乐。这三个声道必须融合在一起并彼此平衡调和，这样才能产生必要的侧重点，进而实现影片所想达到的效果。针对以上提到的三种声道所展开的话题将在后文中一一进行讨论。这些话题包括对话、同步和不同步音效，以及音乐。

让我们从“对话”开始。与舞台戏剧相同，对话的作用是讲述故事并表达角色的感想和动机。随着电影的角色化，观众常常区分不出角色与演员之间会存在什么差別。于是，举个例子来说，演员Humphrey Bogart 就是片中人物Sam Spade；角色特征与真人特征似乎融合在了一起，难分彼此。这也许是因为表演者本人的音质提供了角色构成的一个基本元素。

Let us start with dialogue. As is the case with stage drama, dialogue serves to tell the story and expresses feelings and motivations of characters as well. Often with film characterization the audience perceives little or no difference between the character and the actor. Thus, for example, the actor Humphrey Bogart is the character Sam Spade; film personality and life personality seem to merge. Perhaps this is because the very texture of a performer's voice supplies an element of character.

当声音特质配合了表演者的容貌和手势，一个完整而非常真实的人物就出现了。观众看到的不是一个演员在展示自己的技艺，而是另一个普通人在与他的人生进行着挣扎搏斗。这样一点颇为有趣：如何使用对话以及到底使用多少数量的对话在不同的电影中差别极大。比方说，在《2001》这部非常成功的科幻电影中，并没有使用很多对话，出现的少量对话也大部分都是平淡无味的，几乎没有什么内在意趣。通过这种方式，电影拍摄者得以描绘出Thomas Sobochack和Vivian Sobochack在《电影简介》中所说到的那种效果：“相比于人类创造出来的宏伟科技和大千宇宙的视觉美感，个人的反应是多么的渺小不足”。

而另一方面，喜剧电影《育婴奇谭》则给出了几乎没有停歇、飞快得惊人的对话。这种对话的使用不但突出了Katherine Hepburn所扮演角色的滑稽荒谬，而且也强调了电影本身的荒诞和由此产生的幽默诙谐。观影者被从一个噱头抛向另一个噱头，从一场对话拉入另一场对话，根本来不及做出任何反应。观众们置身于一场各种行为快速切換的旋风之中，仅仅是努力跟上情节发展就已很不容易了。这部电影代表着纯粹的逃避现实主义风格——一大原因就在于其中凌乱癫狂的对话。

When voice textures fit the performer's physiognomy and gestures, a whole and very realistic persona emerges. The viewer sees not an actor working at his craft, but another human being struggling with life. It is interesting to note that how dialogue is used and the very amount of dialogue used varies widely among films. For example, in the highly successful science-fiction film 2001, little dialogue was evident, and most of it was banal and of little intrinsic interest. In this way the film-maker was able to portray what Thomas Sobochack and Vivian Sobochack call, in An Introduction to Film, the 'inadequacy of human responses when compared with the magnificent technology created by man and the visual beauties of the universe'.

同步音效指的是那些与银幕上正在出现的画面同步或相匹配的声音。比方说，如果影片中的某个角色正在弹钢琴，那么钢琴的声音就会播放出来。同步的各种声音増加了影片的真实感并且有助于营造出某种特定的氛围。例如，一扇门被打开时发出的“咔嗒”声也许仅仅是为了向观众证明此处展示的场景是真实的，而观众可能也仅仅只是在潜意识中注意到了这个意料之中的声响。然而，如果开门的“咔嗒”声是一个即将到来的恶性事件——例如一场入室盗窃——之中的组成部分，影片混音师则有可能会刻意放大音量来引起观众的注意，这能有助于将观众卷入悬念时刻。

另一方面，不同步音效并不匹配于银幕上任何可见的声音来源。之所以运用这样的音效，是为了提供某种恰当的微妙情绪氛围，同时也有可能増加影片的真实感。比如，在影片前景的声音和画面正在描述两个人进行争吵的时候，影片拍摄者有可能会选择救护车的汽笛声作为背景声音。这种不同步的救护车汽笛声突出了争吵所带来的精神伤害；而与此同时，汽笛的声音还增加了影片的真实感，因为它提示了影片的城市背景设定。

The comedy Bringing Up Baby, on the other hand, presents practically non-stop dialogue delivered at breakneck speed. This use of dialogue underscores not only the dizzy quality of the character played by Katherine Hepburn, but also the absurdity of the film itself and thus its humor. The audience is bounced from gag to gag and conversation to conversation; there is no time for audience reflection. The audience is caught up in a whirlwind of activity in simply managing to follow the plot. This film presents pure escapism - largely due to its frenetic dialogue.

我们大概都已对电影中的背景音乐相当熟悉了，它们在影片中如此无处不在，以至于只在没有出现的时候我们才能注意到。我们知道它被用来渲染情绪和韵律。它一般不会喧宾夺主引人关注，而是为影片中所刻画的故事和/或人物提供了某种基调或情绪态度。此外，背景音乐还常常能够预示一种氛围上的变化。比方说，凌乱失调的音乐可以在电影中用来暗示一场正在到来(但目前还并不明显可见)的危险或灾难。

背景音乐可以通过在不同场景之间建立联系来帮助观众理解剧情。例如，与某个角色或场景有关的某个特定的乐曲主题可以在影片中不同的部位反复出现，由此来提醒观众注意到其核心主旨或主题思想。

Synchronous sound effects are those sounds which are synchronized or matched with what is viewed. For example, if the film portrays a character playing the piano, the sounds of the piano are projected. Synchronous sounds contribute to the realism of film and also help to create a particular atmosphere. For example, the 'click' of a door being opened may simply serve to convince the audience that the image portrayed is real, and the audience may only subconsciously note the expected sound. However, if the 'click' of an opening door is part of an ominous action such as a burglary, the sound mixer may call attention to the 'click' with an increase in volume; this helps to engage the audience in a moment of suspense.

电影声音同时包含传统和创新。我们已经逐渐学会了预期在飞速追车的场景中音乐一定会加速，而在恐怖电影中则必定会有嘎吱作响的门声。然而，注意到这样一点也是极其重要的：声音往往是以一种十分精妙出色的方式被人们所感知。音效的作用通常在很大程度上是微妙难察的，常常只有我们的潜意识思维才会注意到它们。除了关注影片的空间效果之外，我们需要刻意培养自己注意电影音效的能力，这样才能真正欣赏到这种在20世纪里如此鲜活而富有生机的艺术形式——现代电影。

Asynchronous sound effects, on the other hand, are not matched with a visible source of the sound on screen. Such sounds are included so as to provide an appropriate emotional nuance, and they may also add to the realism of the film. For example, a film-maker might opt to include the background sound of an ambulance's siren while the foreground sound and image portrays an arguing couple. The asynchronous ambulance siren underscores the psychic injury incurred in the argument; at the same time the noise of the siren adds to the realism of the film by acknowledging the film's city setting.

We are probably all familiar with background music in films, which has become so ubiquitous as to be noticeable in its absence. We are aware that it is used to add emotion and rhythm. Usually not meant to be noticeable, it often provides a tone or an emotional attitude toward the story and/or the characters depicted. In addition, background music often foreshadows a change in mood. For example, dissonant music may be used in film to indicate an approaching (but not yet visible) menace or disaster.

Background music may aid viewer understanding by linking scenes. For example, a particular musical theme associated with an individual character or situation may be repeated at various points in a film in order to remind the audience of salient motifs or ideas.

Film sound comprises conventions and innovations. We have come to expect an acceleration of music during car chases and creaky doors in horror films. Yet, it is important to note as well that sound is often brilliantly conceived. The effects of sound are often largely subtle and often are noted by only our subconscious minds. We need to foster an awareness of film sound as well as film space so as to truly appreciate an art form that sprang to life during the twentieth century - the modern film.