Unity Basic Course: Sound and Sound Import

1. Introduction

Unity is a very powerful engine for game development, and among its various features, sound is a crucial element that enhances the immersion of the game. In this article, we will take a closer look at how Unity handles sound, how to import and use sound files.

2. Importance of Sound

Sound plays a vital role in shaping the atmosphere of a game, stimulating players’ emotions, and emphasizing the unique characteristics of the game. For instance, calm background music enriches the experience during exploration, while tense background sounds heighten the tension in combat situations.

2.1. Types of Sound

The sounds used in Unity can be broadly classified into two categories: Background Music and Sound Effects. Background music primarily forms the overall atmosphere, while sound effects are sounds that are played in response to specific actions or events.

3. Sound Components in Unity

To implement sound in Unity, several components are necessary. These include AudioClip, AudioSource, and AudioListener. Let’s take a closer look at each component.

3.1. AudioClip

AudioClip is the data type used to load sound files. Sound files are typically imported in formats such as WAV, MP3, or Ogg Vorbis. Each file defines a piece of sound that can be played in the game.

3.2. AudioSource

AudioSource is the component that plays AudioClip. It can be added to game objects, making that object the source of the sound. The main properties of AudioSource include:

  • clip: The audio clip to play.
  • volume: The volume of the sound.
  • pitch: The pitch of the sound.
  • loop: Whether to play the sound in a loop.

3.3. AudioListener

AudioListener is the component that receives all sounds in the game. It is typically added to the camera and handles all sounds that the player can hear within the game.

4. Importing Sound Files

The process of importing sound files into Unity is very straightforward. Here is a step-by-step guide to the process.

4.1. Preparing the Files

First, prepare the sound files you want to use. While files in WAV or MP3 format are generally recommended, other formats can also be used as needed.

4.2. Importing into Unity Project

To import sound files into Unity, follow these steps.

  1. Run the Unity Editor.
  2. Select the Assets folder in the Project window.
  3. Drag the prepared sound files into the Assets folder.

4.3. Setting Up Sound Files

To set up the properties of the imported sound files, click on the file and adjust various properties in the Inspector window. Here, you can set the Load Type to determine how the sound is played:

  • Decompress on Load: Loads all data into memory when loading the file. Be cautious if the file size is large.
  • Compressed in Memory: Keeps the data in a compressed form when loaded into memory.
  • Streaming: Plays the file while streaming. Used for large background music tracks.

5. Playing Sound

To play sound, you need to add an AudioSource component to a game object. Follow these steps to do so.

5.1. Adding AudioSource

Select the game object that will play the sound, click the Add Component button in the Inspector window, search for AudioSource, and add it.

5.2. Linking Sound Clips

Drag the imported sound file into the Audio Clip field of the added AudioSource to link it.

5.3. Playing Sound

To play sound, you need to add a script. Let’s add the following simple C# code to the game object to play the sound: 

        
        using UnityEngine;

        public class SoundPlayer : MonoBehaviour
        {
            private AudioSource audioSource;

            void Start()
            {
                audioSource = GetComponent();
                audioSource.Play(); // Play sound
            }
        }

6. Advanced Sound Control

In Unity, you can control sound in various ways beyond basic playback. Settings for volume, pitch, bitrate, and more can provide a richer sound experience.

6.1. Adjusting Volume

You can adjust the volume of the sound using the volume property of AudioSource. For example, you can adjust the volume as follows: 

        
        audioSource.volume = 0.5f; // Volume 50%

6.2. Adjusting Pitch

You can adjust the pitch of the sound using the pitch property of AudioSource. The default pitch is 1.0, and setting it to 2.0 makes the sound twice as high. 

        
        audioSource.pitch = 1.5f; // 50% higher

7. Using the Mixer

By using Unity’s Audio Mixer feature, you can finely adjust various sound effects and volume settings. Let’s learn how to adjust sound output and effects using the mixer.

7.1. Creating a Mixer

Right-click in the Assets folder and select Create > Audio Mixer to create a new mixer. The created mixer can be modified in the Audio Mixer window.

7.2. Linking Audio Sources to the Mixer

Modify the Output property of each AudioSource to link it to the group of the created mixer. This allows you to adjust sound using the settings of the mixer.

8. Optimizing Sound

Optimizing sound in games is important for improving performance and minimizing memory usage. Here are some optimization methods.

8.1. Removing Unnecessary Sounds

Unused sound files should be removed from the project. This helps reduce memory usage and optimizes the size of the build file.

8.2. Optimizing Audio Formats

Choosing the appropriate audio format is also important. For example, background music can use compressed formats like MP3 or Ogg Vorbis to save memory. Sound effects may do better with the WAV format.

9. Conclusion

Handling sound in Unity offers various methods and is fundamental yet diverse. In this tutorial, we learned about the importance of sound along with the basic methods for importing, playing, and controlling it, as well as advanced features like mixing and optimization methods. Building on this foundation, you can create unique sounds for your own games.

10. References

If you want more information, refer to the following resources: