Audacity on Windows is only available as a 32-bit application that may be used on 32-bit or 64-bit systems. For macOS Audacity 3.x is 64-bit. Free, open source, cross-platform audio software. Audacity is an easy-to-use, multi-track audio editor and recorder for Windows, Mac OS X, GNU/Linux and other operating systems. Developed by a group of volunteers as open source and offered free of charge. Amazing support community.
If you’re into sound editing, you must have probably heard about Audacity, and it’s highly possible that you’re already using it for your projects. Whether it’s sound mixing, voiceovers or podcasts, it does the job for you easily. The open source and free software is so powerful that it’s recommended as a strong alternative to even the commercial audio editing software out there. We have covered Audacity several times before, so here’s a quick rundown of the most useful tips and tricks offered inside the software. You’ll come across tips which are directed more towards creating podcasts and voiceovers for YouTube videos.
Amplify your tracks
This may be the most common feature used in Audacity, in fact many specifically have downloaded and installed this software just to amplify their recordings. This feature is useful when your recording device has a lower capture volume. It also works the other way, so if it’s too loud, you can decrease the peak by entering a negative value. And it’s fairly simple. Once you’ve opened the audio track, you can both select the entire track or just a portion, and then go to Effect > Amplify. Then you can enter the Amplification value in positive or negative based on whether you want to increase or decrease the peak.
Change the pitch
Ever wondered how to convert a normal voice recording into that squeaky and chipmunky pitch? It’s really easy on Audacity. With an area selected in the track, go to Effects > Change pitch and move the slider or enter a value in Percent Change under the Frequency section. You don’t need to fiddle around with the top section if you’re only dealing with a normal voice recording. You can increase and decrease the pitch by adding in a positive or negative value respectively. Higher the pitch percent change, the more squeaky the voice, whereas lesser the pitch, the deeper the voice. So now you know how to get the chipmunk voice.
- Audacity is free of charge. No registration or hardware purchase required. 64-Bit Audacity on Windows is only available as a 32-bit application that may be used on 32-bit or 64-bit systems.
- How to Download and Install AudacityIn this video tutorial, I'll be showing you how to download and install Audacity. Website Link: http://www.audacityteam.o.
Removing silent portions mid-way
While recording for your video voiceovers and podcasts, there are silences in between as you speak throughout the length. The final version sounds awkward hence it’s always better to get rid of these silent gaps, to improve the flow. You may wonder that you would have to grind and remove all the silent portions by manually selecting and deleting them. But Audacity has a tool to achieve that. Go to Effect > Truncate Silence and select Truncate Detected Silence under the Action section. Once applied, you’ll notice that all the silent gaps have been removed. If you want to get more specific to the level of silence you want to achieve, the Detect Silence section in the same menu lets you select the level of silence you want to remove. But if you’re satisfied with the default setting, then you don’t need to fiddle around with it.
Noise removal
You’re done recording your clip but when you play it back, you hear a lot of ambient or background noise that the mic picked up. Obviously, it’s an unwanted noise and it’s easy to remove them. First select the silent area where you don’t have any necessary sound. Then go to Effect > Noise Reduction and click on Get Noise Profile under Step 1. This is how it acquires the ambient noise signals which can be filtered out. After getting the noise profile, open up Noise Reduction again and hit Ok in the Step 2. Now the track will sound significantly noise free if you play it.
Normalise audio levels
To achieve good quality audio in voice recording, it’s essential to maintain a steady and constant distance from the mic. Otherwise, you might notice a random rise and fall in the sound levels which sounds really bad. Audacity has a tool built-in that normalises the varying sound levels so that you achieve a favourable audio track. This works really great if your audio is too loud and you need to bring down the levels. Go to Effect > Normalize and add the required value, varying from -3dB to -6dB and so on, until you hit the right spot.
Change the tempo
You might not be happy with the tempo of the audio you recorded and are considering re-recording at a different pace. In Audacity, you’ll be able to do it right through the Change Tempo effect. As usual, go to Effect > Change Tempo and change the value of Percent Change by entering the value or using the slider. Use the Preview button if you aren’t sure and when you’ve hit the right tempo, apply it throughout the track. This is a great tool if you tend to speak slowly while reading a script but want to use a faster tempo in your video or podcast.
Adjust the equalisation
The recorded clip as mentioned above isn’t always the best and lacks proper tuning for bass and treble. This highly depends on how good your mic captures the audio. If you aren’t satisfied with the tuning, you can change the equalisation manually. Select the entire clip and head over to Effect > Equalization. Here, you’ll be able to adjust the curve according to your preference of boosting the bass or treble. There are presets already available which can be cycled through the Select Curve dropdown list or manually tinker with the curve and save it. To start off, it’s always better to hit Flatten and then change the curve. But then again, as with most equalisers, use your own judgement regarding the settings based on how it sounds.
Using chains to apply multiple effects
When you’re editing audio clips routinely with the same set of adjustments, then Audacity can automate all those adjustments with a single tool. By applying chains to tracks, you can implement a set of effects together in one go. To add a new chain, go to File > Edit Chains and you’ll open a window where you have an MP3 Conversion chain already added as an example. To insert a new chain, select Add and give it a name for example Podcast. To add the effects, click on Insert and scroll through the effects and pick the one you need. Once selected, you can edit the parameters of that effect, which is the same as adding the effect to your track. And one by one you’ll be able to add multiple effects in one single chain. Whenever you need to apply that chain to the entire or a selected portion of the track, go to File > Apply Chain, then select the desired chain and click on Apply on Current Project.
This article was first published in November 2016 issue of Digit magazine. To read Digit's articles first, subscribe here or download the Digit e-magazine app for Android and iOS. You could also buy Digit's previous issues here.
This page describes audio file formats which can be exported to using the Export Audio / Export Selected Audio and Export Multiple dialogs. To export to MP3 you must install the optional LAME encoder and to export to formats listed as 'FFmpeg' you must install the optional FFmpeg library.
Many format types have size, quality or encoding options. Select the format type then click the button in the Export Audio / Selected Audio or Export Multiple dialog to view the options for that selected format. You can click the first link in each format listed below to view the Options page for that format. |
Contents
Uncompressed format types
The following are all uncompressed audio formats in which every sample of sound is represented by a binary number. The most common uncompressed formats are WAV and AIFF.
There is no loss of quality compared to the original audio when playing uncompressed formats, except for some possible loss of low frequencies in the 4-bit (A)DPCM formats. Those 4-bit formats and the lossless 8-bit U-Law/A-Law formats save file size by reducing their bit depth, in a similar way that any of the uncompressed formats can be made proportionately smaller by reducing their sample rate (and thus reducing the high frequencies they can contain). GSM 6.10 WAV (mobile) will also exhibit considerable loss of quality as it was a format designed for mobile telephony.
- Other uncompressed files: includes all the uncompressed audio formats that Audacity can export, including 4-bit (A)DPCM, 8-bit U-Law/A-Law, 24-bit, 32-bit and 64-bit options. Also GSM 6.10 WAV (mobile) which produces a mono WAV file encoded with the compressed, lossy GSM 6.10 codec as used in mobile telephones. This menu item defaults to WAV (Microsoft) signed 16-bit PCM on Windows and Linux and to AIFF (Apple/SGI) signed 16-bit PCM on Mac.
- AIFF (Apple/SGI) signed 16-bit PCMNo options for this format: AIFF is a lossless format that can both be played on Mac and Windows computers, though it is far more likely to be selected by Mac users. AIFF 16-bit PCM is suitable whenever you want to burn your exported file to an audio CD.
- WAV (Microsoft) signed 16-bit PCMNo options for this format: WAV is a lossless format that can both be played on Windows or Mac computers. WAV 16-bit PCM is eminently suitable whenever you want to burn your exported file to an audio CD.
- WAV (Microsoft) signed 24-bit PCMNo options for this format: 24-bit PCM gives higher quality than 16-bit PCM, but takes up more space.
- WAV (Microsoft) 32-bit floatNo options for this format: 32-bit float WAV is a lossless format, a maximum quality 'raw capture' file. 32-bit float resolution gives the highest quality of the three uncompressed choices, but takes twice the storage space on disk compared to 16-bit resolution. It will not play on many players or player apps. It is mostly useful as a backup archive of raw captured recordings or finished projects.
16-bit WAV and AIFF formats produce large files and are best-suited for use on computers rather than portable players or devices.
Size limits for WAV and AIFF PCM-encoded files
WAV and AIFF files are limited to a maximum size of 4GB (this is a general restriction and not an Audacity one).
See the following table for how this translates to approximate time durations:
Sample Format | Stereo | Mono |
16-bit (default) | 6h:45m | 13h:31m |
24-bit | 4h:30m | 9h:01m |
32-bit | 3h:22m | 6h:45m |
These timings are the theoretical maximum times. You would be well-advised to restrict yourself to slightly lower limits to afford some head-room. |
Compressed format types
Size-compressed formats produce files that are usually significantly smaller than uncompressed formats, as seen in the table below. The file formats that are significantly smaller are always of lower quality than the original audio, but are well suited for use on portable devices where storage space is limited.
- MP3 Files:MP3 is a popular compressed, lossy format producing much smaller files than WAV or AIFF, at the expense of some loss of quality. You must download the optional LAME encoder to export to MP3.
- OGG Vorbis Files:Ogg Vorbis is the compressed, lossy Vorbis codec in an OGG container. Vorbis offers higher quality than MP3 for the same file size, and is useful for good quality small-sized mono files, but fewer applications can play the OGG format.
- FLAC Files:FLAC is a compressed but lossless format, giving much larger file sizes than MP3 and OGG but only about half the size of WAV.
- MP2 Files:MP2 is a compressed, lossy format similar to MP3, producing slightly larger files than MP3 for the same quality.
External program
- (external program): sends audio via the command-line to any executable binary application either for processing or for encoding as a file. This is a method to export using an alternative compressed or uncompressed encoder or to a format not otherwise supported by Audacity.
FFmpeg format types (mostly compressed)
The following export types are listed in released builds of Audacity on Windows and Mac, and in other builds where FFmpeg is enabled. They will only function if you install the optional FFmpeg library.
The following four formats are small-sized compressed formats giving file sizes comparable to or smaller than MP3.
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- M4A (AAC) Files (FFmpeg): Advanced Audio Coding is a compressed, lossy format used in Apple applications, generally achieving slightly better quality than MP3 for the same file size. By default, the exported file will be given an 'm4a' extension. Optional permitted extensions: .mp4, .m4r (ringtone) and .3gp (mobile).
- AC3 Files (FFmpeg): the common name used for the compressed, lossy format used in Dolby Digital.
- AMR (narrow band) Files (FFmpeg): the Adaptive Multi-Rate codec is a patented compression scheme optimized for speech, but also used for mobile telephone ringtones. The wide band variant uses higher bandwidth for higher quality.
- WMA (version 2) Files (FFmpeg): Windows Media Audio v2 is a compressed, lossy format developed by Microsoft. Optional permitted extensions: .asf or .wmv.
Custom FFmpeg Export
- Custom FFmpeg Export: Allows interface-based export of some additional compressed or uncompressed formats not listed above, and options for exporting formats containing alternative codecs (for example, WAV format containing MP3 or OGG format containing FLAC). Note: not all formats and codecs are compatible, and some exports might result in zero-byte or invalid files if FFmpeg does not support the combination chosen. The most flexible method to export to more formats using FFmpeg (or using any alternative encoder of your choice) is therefore to select (external program) as above and use the command-line encoder. See How can I export to formats not listed in the Export Audio Dialog? for more information.
File size and channel comparisons by export format
The following table gives typical achieved mono and stereo file sizes with different formats at default Audacity settings (that is, 44100 Hz sample rate and default bit rate or quality settings in the case of compressed formats). Where VBR compression is employed, the achieved size will vary depending on the content.
Some formats can be exported as multi-channel files containing more than two channels, if you enable this at 'Use custom mix' in the Import / Export Preferences. The final column in the table shows the maximum number of channels Audacity can export for each format. Some formats may theoretically support more channels than Audacity can export.
Format | Lossy | Compression | File size (MB per minute): | File size limit: | Channels | |
mono | stereo | |||||
WAV 16-bit PCM | No | None | 5.0 | 10.0 | 4 GB(1) | 32 |
AIFF 16-bit PCM | No | None | 5.0 | 10.0 | 4 GB(1) | 32 |
FLAC 16-bit | No | VBR | 2.5 | 5.0 | 8 | |
M4A (AAC) | Yes | VBR | - | 1.1 | 32(2) | |
WMA v2 | Yes | CBR | 1.3 | 1.3 | 8(3) | |
AC3 | Yes | CBR | 1.1 | 1.1 | 7 | |
MP2 | Yes | CBR | 1.1 | 1.1 | 2 | |
MP3 | Yes | CBR (optional VBR) | 1.0 (CBR) | 1.0 (CBR) | 2 | |
Ogg Vorbis | Yes | VBR | 0.5 | 1.0 | 32 | |
GSM 6.10 WAV | Yes | CBR | 0.5 | - | 1 | |
AMR (NB) | Yes | CBR | 0.1 | - | 1 |
(1) | The practical file size limit is 2 GB in many player applications due to their interpretation of the file size header. This also applies to 24-bit and 32-bit files where those bit depths are valid. |
(2) | More than 2 channels output is not supported with the recommended FFmpeg 2.2.2 library, unless you export using (external program) with a command that tells Audacity to explicitly use the native FFmpeg encoder. This produces maximum 6 channels. For up to 8 channels, point the same command to the latest FFmpeg-git. |
(3) | A maximum of 2 channels can be written using the 'WMA (version 2) Files (FFmpeg)' export choice or FFmpeg at the command-line using (external program). To encode other WMA formats, export using (external program) and point to a command-line WMA encoder. lvqcl's command-line WMA encoder can export as WMA V9, WMA Lossless and WMA 10 Professional (but limited to maximum 6 channels, despite WMA 10 Professional supports 8 channels). |
Audacity For Mobile
Exporting to formats not listed in the Export Audio Dialog
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If you install the optional FFmpeg library you can use the (FFmpeg) choices in the Export Audio Dialog to export M4A (AAC), AC3, AMR (narrow band) and WMA. If you do not see a choice for one of those specific FFmpeg formats, then the build of FFmpeg you are linking to was not compiled to support encoding in that format.
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The most flexible method to export to more formats is to choose (external program) in the Export Audio Dialog which opens the dialog for Audacity's command-line encoder. Point your command to an encoder that supports the format you want to write to, which could be FFmpeg or some other encoder (for example, an alternative AAC or MP3 encoder). On Windows, the recommended EXE installer of FFmpeg includes an ffmpeg.exe which you can use for this purpose. On Mac, you can download a standalone 'ffmpeg' binary if you search online.