Sound / Audio / Music. How do we obtain sounds? We sample them! We sample them!

Sound / Audio / MusicSound / Audio / Music

How do we obtain sounds?How do we obtain sounds?

How do we obtain sounds?How do we obtain sounds?

We sample them!We sample them!

Sampling: – analog to digital – continuous to discrete

Must be done carefully!

stereostereo

Problem:

Correct and incorrect sampling rates (sampling frequency; x direction).

Problem:

Quantization (not enough bits in our ADC; y direction).

Audio File FormatsAudio File Formats

Unity supported audio file formatsUnity supported audio file formats MP(EG)1/2/3, Ogg Vorbis, wav, and AIFFMP(EG)1/2/3, Ogg Vorbis, wav, and AIFF mono or stereomono or stereo

Torque supported audio file formatsTorque supported audio file formats .wav files & .ogg files (Ogg Vorbis).wav files & .ogg files (Ogg Vorbis) mono or stereomono or stereo


Compression (AKA CODECS) types:Compression (AKA CODECS) types: lossy vs. losslesslossy vs. lossless

Ex.Ex. 6.1M mp3 file converted to a 5.1M .ogg 6.1M mp3 file converted to a 5.1M .ogg

file and a 33.9M .wav filefile and a 33.9M .wav file 7.6M mp3 file converted to a 8.6M .ogg 7.6M mp3 file converted to a 8.6M .ogg

file and a 83.2M .wav filefile and a 83.2M .wav file But game engines may pause while But game engines may pause while

decompressing large files.decompressing large files.


CompressedCompressed Compress sounds by choosing the compressed option from inside the Compress sounds by choosing the compressed option from inside the

Editor. The audio data will be small, but will cost CPU cycles to decode at Editor. The audio data will be small, but will cost CPU cycles to decode at play time. Depending on the target, Unity will encode the audio to either play time. Depending on the target, Unity will encode the audio to either Ogg Vorbis (Mac/PC/Consoles) or MP3 (Mobile platforms).Ogg Vorbis (Mac/PC/Consoles) or MP3 (Mobile platforms).

For the best sound quality supply the audio in an uncompressed format For the best sound quality supply the audio in an uncompressed format such as WAV or AIFF (containing PCM data) and let Unity do the encoding.such as WAV or AIFF (containing PCM data) and let Unity do the encoding.

If only targeting Mac/PC (standalones, webplayers) importing an Ogg If only targeting Mac/PC (standalones, webplayers) importing an Ogg Vorbis file will not degrade the quality. But converting to mobile Vorbis file will not degrade the quality. But converting to mobile platforms will force a re-encode to MP3 and cause a slight quality platforms will force a re-encode to MP3 and cause a slight quality degradation. Same goes for importing MP3, when only targeting mobile degradation. Same goes for importing MP3, when only targeting mobile platforms.platforms.

NativeNative Use Native (WAV, AIFF) audio for short sound effects. The audio data will Use Native (WAV, AIFF) audio for short sound effects. The audio data will

be larger, but sounds won't need to be decoded at play time.be larger, but sounds won't need to be decoded at play time.

Audio File Editor: Audacity Audio File Editor: Audacity (audacity.sourceforge.net)(audacity.sourceforge.net)

Audacity: record, play, etc.Audacity: record, play, etc.

Audacity: select and cutAudacity: select and cut

Audacity: after cutAudacity: after cut

Audacity: Fit-in-WindowAudacity: Fit-in-Window

Audacity: after Fit-in-Audacity: after Fit-in-WindowWindow

Audacity: add reverb effect to Audacity: add reverb effect to selectionselection

Audacity: add reverb effect to Audacity: add reverb effect to selectionselection

Add a cheesy wah wah effect to Add a cheesy wah wah effect to your selection (but preview it your selection (but preview it

first).first).

http://www.youtube.com/watch?v=Ovld0LDOBg0http://www.youtube.com/watch?v=OEJh2FFUUoU

http://www.youtube.com/watch?v=OEJh2FFUUoU




Audio in UnityAudio in Unity

Audio Components Audio Components Audio ClipAudio Clip Audio Listener Audio Listener Audio Source Audio Source Audio EffectsAudio Effects (PRO only) (PRO only)

Audio Low Pass FilterAudio Low Pass Filter (PRO only) (PRO only) Audio High Pass FilterAudio High Pass Filter (PRO only) (PRO only) Audio Echo FilterAudio Echo Filter (PRO only) (PRO only) Audio Distortion FilterAudio Distortion Filter (PRO only) (PRO only) Audio Reverb FilterAudio Reverb Filter (PRO only) (PRO only) Audio Chorus FilterAudio Chorus Filter (PRO only) (PRO only)

Reverb ZonesReverb Zones


Audio Components Audio Components

The following slides were compiled from The following slides were compiled from information available from the excellent Unity information available from the excellent Unity reference manual reference manual (http://unity3d.com/support/documentation/Co(http://unity3d.com/support/documentation/Components/index.html).mponents/index.html).

AUDIO CLIPAUDIO CLIP


Audio Components: Audio ClipAudio Components: Audio Clip

Audio Clips are audio data used by Audio Audio Clips are audio data used by Audio Sources. Unity supports mono, stereo and multi Sources. Unity supports mono, stereo and multi (up to 8) channels audio assets. Unity (up to 8) channels audio assets. Unity supports importing the following audio file supports importing the following audio file formats: .aif, .wav, .mp3, and .ogg.formats: .aif, .wav, .mp3, and .ogg.


Audio Components: Audio ClipAudio Components: Audio Clip


Audio Components: Audio ClipAudio Components: Audio Clip Audio FormatAudio Format The specific format that will be used for the sound at The specific format that will be used for the sound at

runtime.runtime. NativeNative Larger file size, higher quality. Best for very short sound effects.Larger file size, higher quality. Best for very short sound effects. CompressedCompressed Smaller file size, lower/variable quality. Best for Smaller file size, lower/variable quality. Best for

medium length sound effects and music.medium length sound effects and music. 3D Sound3D Sound If enabled, the sound will play back in 3D space. Both If enabled, the sound will play back in 3D space. Both

Mono and Stereo sounds can be played in 3D.Mono and Stereo sounds can be played in 3D. Force to monoForce to mono If enabled, the audio clip will be down-mixed to a single If enabled, the audio clip will be down-mixed to a single

channel sound.channel sound.


Audio Components: Audio Clip (cont’d.)Audio Components: Audio Clip (cont’d.) Load TypeLoad Type The way Unity load audio assets runtime.The way Unity load audio assets runtime. Decompress on loadDecompress on load Decompress sounds upon load. Use this for smaller Decompress sounds upon load. Use this for smaller

compressed sounds to avoid the performance overhead of decompressing on the compressed sounds to avoid the performance overhead of decompressing on the fly. Beware that a compressed sound will use ~10x more memory that when fly. Beware that a compressed sound will use ~10x more memory that when decompressed, so don't use this for large files.decompressed, so don't use this for large files.

Compressed in memoryCompressed in memory Keep sounds compressed in memory and decompress Keep sounds compressed in memory and decompress while playing. This have a slight performance overhead (esp. for Ogg/Vorbis while playing. This have a slight performance overhead (esp. for Ogg/Vorbis compressed files) so only use this for bigger files.compressed files) so only use this for bigger files.

Stream from discStream from disc Stream audio data directly from disc. This uses a fraction of the Stream audio data directly from disc. This uses a fraction of the original sounds size of memory. Use this for your music or very long tracks. original sounds size of memory. Use this for your music or very long tracks. Depending on the hardware, a general advice is to keep this down to 1-2 Depending on the hardware, a general advice is to keep this down to 1-2 simultaneously streams.simultaneously streams.

CompressionCompression Amount of Compression to be applied to a Compressed clip. Amount of Compression to be applied to a Compressed clip. Statistics about file size can be seen beneath the slider. It is suggested to drag Statistics about file size can be seen beneath the slider. It is suggested to drag the slider to a place that leaves the playback "good enough" but still at a small the slider to a place that leaves the playback "good enough" but still at a small enough size to meet your file size/distribution needs.enough size to meet your file size/distribution needs.

AUDIO LISTENERAUDIO LISTENER


Audio Components: Audio Listener Audio Components: Audio Listener The Audio Listener acts as a microphone-like device. The Audio Listener acts as a microphone-like device.

It receives input from any given Audio Source in the It receives input from any given Audio Source in the scene and plays sounds through the computer scene and plays sounds through the computer speakers.speakers.

For most applications it makes the most sense to For most applications it makes the most sense to attach the listener to the Main Camera.attach the listener to the Main Camera.

If an audio listener is within the boundaries of a If an audio listener is within the boundaries of a Reverb Zone reverberation is applied to all audible Reverb Zone reverberation is applied to all audible sounds in the scene. (PRO only) Furthermore, Audio sounds in the scene. (PRO only) Furthermore, Audio Effects can be applied to the listener and it will be Effects can be applied to the listener and it will be applied to all audible sounds in the scene.applied to all audible sounds in the scene.

AUDIO SOURCEAUDIO SOURCE


Audio Components: Audio SourceAudio Components: Audio Source The Audio Source plays back an Audio Clip in the scene. The Audio Source plays back an Audio Clip in the scene.

If the Audio Clip is a 3D clip, the source is played back If the Audio Clip is a 3D clip, the source is played back at a given position and will attenuate over distance. The at a given position and will attenuate over distance. The audio can be spread out between speakers (stereo to audio can be spread out between speakers (stereo to 7.1) (Spread) and morphed between 3D and 2D 7.1) (Spread) and morphed between 3D and 2D (PanLevel). This can be controlled over distance with (PanLevel). This can be controlled over distance with falloff curves. Also, if the listener is within 1 or multiple falloff curves. Also, if the listener is within 1 or multiple Reverb Zones, reverberations is applied to the source. Reverb Zones, reverberations is applied to the source. (PRO only) Individual filters can be applied to each (PRO only) Individual filters can be applied to each audio source for an even richer audio experience. See audio source for an even richer audio experience. See Audio Effects for more details.Audio Effects for more details.


Audio Components: Audio SourceAudio Components: Audio Source

The Audio Source gizmo in the Scene View and its settings in the inspector.


Audio Components: Audio SourceAudio Components: Audio Source Rolloff mode: How fast the sound fades. Rolloff mode: How fast the sound fades.

The higher the value, the closer the The higher the value, the closer the Listener has to be before hearing the Listener has to be before hearing the sound.sound.


Audio Components: Audio SourceAudio Components: Audio Source Rolloff mode types:Rolloff mode types:

1.1. Logarithmic rolloff: The sound is loud when you Logarithmic rolloff: The sound is loud when you are close to the audio source, but when you get are close to the audio source, but when you get away from the object it decreases significantly away from the object it decreases significantly fast.fast.

2.2. Linear rolloff: The more far away from the audio Linear rolloff: The more far away from the audio source you go, the less you can hear it.source you go, the less you can hear it.

3.3. Custom rolloff: The sound from the audio source Custom rolloff: The sound from the audio source behaves accordingly to how you set the graph of behaves accordingly to how you set the graph of roll offs.roll offs.


Audio Components: Audio SourceAudio Components: Audio Source Rolloff mode types:Rolloff mode types:

1.1. Logarithmic RolloffLogarithmic Rolloff

2.2. Linear RolloffLinear Rolloff

3.3. Custom RolloffCustom Rolloff


Audio Components: Audio SourceAudio Components: Audio Source

Distance FunctionsDistance Functions There are several properties of the audio that can be modified as There are several properties of the audio that can be modified as

a function of the distance between the audio source and the a function of the distance between the audio source and the audio listener.audio listener.

Volume:Volume: Amplitude(0.0 - 1.0) over distance.Amplitude(0.0 - 1.0) over distance. Pan:Pan: Left(-1.0) to Right(1.0) over distance.Left(-1.0) to Right(1.0) over distance. Spread:Spread: Angle (degrees 0.0 - 360.0) over distance.Angle (degrees 0.0 - 360.0) over distance. Low-Pass (only if LowPassFilter is attached to the AudioSource):Low-Pass (only if LowPassFilter is attached to the AudioSource):

Cutoff Frequency (22000.0-10.0) over distance.Cutoff Frequency (22000.0-10.0) over distance.


Audio Components: Audio Source propertiesAudio Components: Audio Source properties Audio ClipAudio ClipReference to the sound clip file that will be played.Reference to the sound clip file that will be played. MuteMute If enabled the sound will be playing but muted.If enabled the sound will be playing but muted. Bypass EffectsBypass Effects This Is to quickly "by-pass" filter effects applied to the audio This Is to quickly "by-pass" filter effects applied to the audio

source. An easy way to turn all effects on/off.source. An easy way to turn all effects on/off. Play On AwakePlay On Awake If enabled, the sound will start playing the moment the scene If enabled, the sound will start playing the moment the scene

launches. If disabled, you need to start it using the Play() command from scripting.launches. If disabled, you need to start it using the Play() command from scripting. LoopLoop Enable this to make the Audio Clip loop when it reaches the end.Enable this to make the Audio Clip loop when it reaches the end. PriorityPriority Determines the priority of this audio source among all the ones that coexist Determines the priority of this audio source among all the ones that coexist

in the scene. (Priority: 0 = most important. 256 = least important. Default = 128.). in the scene. (Priority: 0 = most important. 256 = least important. Default = 128.). Use 0 for music tracks to avoid it getting occasionally swapped out.Use 0 for music tracks to avoid it getting occasionally swapped out.

VolumeVolume How loud the sound is at a distance of 1 world unit (1 meter) from the Audio How loud the sound is at a distance of 1 world unit (1 meter) from the Audio Listener.Listener.

PitchPitch Amount of change in pitch due to slowdown/speed up of the Audio Clip. Amount of change in pitch due to slowdown/speed up of the Audio Clip. Value 1 is normal playback speed.Value 1 is normal playback speed.

3D Sound Settings3D Sound Settings Settings that are applied to the audio source if the is a 3D Sound.Settings that are applied to the audio source if the is a 3D Sound.


Audio Components: Audio Source properties Audio Components: Audio Source properties (cont’d.)(cont’d.)

Pan LevelPan Level Sets how much the 3d engine has an effect on the audio source.Sets how much the 3d engine has an effect on the audio source. SpreadSpread Sets the spread angle to 3d stereo or multichannel sound in speaker space.Sets the spread angle to 3d stereo or multichannel sound in speaker space. Doppler LevelDoppler Level Determines how much doppler effect will be applied to this audio Determines how much doppler effect will be applied to this audio

source (if is set to 0, then no effect is applied).source (if is set to 0, then no effect is applied). Min DistanceMin Distance Within the MinDistance, the sound will stay at loudest possible. Within the MinDistance, the sound will stay at loudest possible.

Outside MinDistance it will begin to attenuate. Increase the MinDistance of a sound to Outside MinDistance it will begin to attenuate. Increase the MinDistance of a sound to make it 'louder' in a 3d world, and decrease it to make it 'quieter' in a 3d world.make it 'louder' in a 3d world, and decrease it to make it 'quieter' in a 3d world.

Max DistanceMax Distance The distance where the sound stops attenuating at. Beyond this The distance where the sound stops attenuating at. Beyond this point it will stay at the volume it would be at MaxDistance units from the listener and point it will stay at the volume it would be at MaxDistance units from the listener and will not attenuate any more.will not attenuate any more.

Rolloff ModeRolloff Mode How fast the sound fades. The higher the value, the closer the How fast the sound fades. The higher the value, the closer the Listener has to be before hearing the sound.Listener has to be before hearing the sound.

2D Sound Settings2D Sound Settings Settings that are applied to the audio source if the is a 3D Sound.Settings that are applied to the audio source if the is a 3D Sound. Pan 2DPan 2D Sets how much the engine has an effect on the audio source.Sets how much the engine has an effect on the audio source.

AUDIO EFFECTSAUDIO EFFECTS


Audio Components Audio Components Audio EffectsAudio Effects (PRO only) (PRO only)



Audio Components Audio Components Audio EffectsAudio Effects (PRO only) (PRO only)


REVERB ZONESREVERB ZONES


Audio Components: Reverb ZonesAudio Components: Reverb Zones Reverb Zones take an Audio Clip and Reverb Zones take an Audio Clip and

distortionates it depending where the audio distortionates it depending where the audio listener is located inside the reverb zone.listener is located inside the reverb zone.

They are used when you want to gradually They are used when you want to gradually change from a point where there is no change from a point where there is no ambient effect to a place where there is ambient effect to a place where there is one. For example when you are entering a one. For example when you are entering a cavern. cavern.


Audio Components: Reverb ZonesAudio Components: Reverb Zones The Audio Reverb Zone gizmo seen in the The Audio Reverb Zone gizmo seen in the

inspector:inspector:


Audio Components: Reverb Zones PropertiesAudio Components: Reverb Zones Properties Min Distance - Represents the radius of the inner Min Distance - Represents the radius of the inner

circle in the gizmo, this determines the zone where circle in the gizmo, this determines the zone where there is a gradually reverb effect and a full reverb there is a gradually reverb effect and a full reverb zone.zone.

Max Distance - Represents the radius of the outer Max Distance - Represents the radius of the outer circle in the gizmo, this determines the zone where circle in the gizmo, this determines the zone where there is no effect and where the reverb starts to there is no effect and where the reverb starts to get applied gradually.get applied gradually.

Reverb Preset - Determines the reverb effect that Reverb Preset - Determines the reverb effect that will be used by the reverb zone.will be used by the reverb zone.

ExamplesExamples

Player sounds (footsteps, utterances)Player sounds (footsteps, utterances) Weapon soundsWeapon sounds Vehicle soundsVehicle sounds Environmental soundsEnvironmental sounds Interface soundsInterface sounds

Converting stereo to mono Converting stereo to mono with Audacitywith Audacity

(Many game engines require mono sources for 3D (Many game engines require mono sources for 3D sound, i.e. sound with volume based upon sound, i.e. sound with volume based upon listener distance.)listener distance.)

1.1. Split stereo track.Split stereo track.2.2. Make both tracks mono.Make both tracks mono.3.3. Use the level control for each track, found on Use the level control for each track, found on

the left of the track, to set to: "Gain: -6 dB". the left of the track, to set to: "Gain: -6 dB". Then when you quick mix, it is guaranteed to Then when you quick mix, it is guaranteed to not clip.not clip.

4.4. Select both tracksSelect both tracks5.5. Project -> Quick Mix.Project -> Quick Mix.6.6. Save mono audio as .wav or .ogg.Save mono audio as .wav or .ogg.

Sounds on the internetSounds on the internet

The altavista.com search engine The altavista.com search engine no no longerlonger allows you to search for allows you to search for audio files (and specific audio file audio files (and specific audio file formats).formats).

Sound/audio exampleSound/audio example

Demo Audacity and “Good Times.”Demo Audacity and “Good Times.” file:///j://pub_html/csc343/slides/gt.aup

(actually an XML file)(actually an XML file) Isolate the bass track.Isolate the bass track.

1.1. lowpass filterlowpass filter

2.2. slow tempo but maintain pitchslow tempo but maintain pitch

1.1. Unity Sound exercise.Unity Sound exercise.

Sound/audio exerciseSound/audio exercise

Unity Sound exercise.Unity Sound exercise.

Documents

Sound / Audio / Music. How do we obtain sounds? We sample them! We sample them!