免費又開源的 Audacity，剪聲音、去雜訊、轉檔夠用嗎

What's new in this version:

Cross-platform Bug Fixes:
* Muting/soloing caused incorrect channel results in exported
stereo files
* Noise Removal and all Nyquist effects pasted the original
unmodified audio at the end of the modified region
* Noise Removal inserted a tail of low level noise at the end
of the modified region
* Nyquist and Compressor plug-ins did not display moving bars
in progress dialogue and over-estimated "Remaining Time"
* Cancelling Nyquist effects deleted unprocessed audio
* Change Speed and Change Tempo failed to modify the original
selection length
* Cut lines invisible
* Fixed various bugs importing multi-stream files via FFmpeg
* File > Export as WAV could be corrupted if overwriting
an imported WAV read direct from the file
* Export multiple "Other uncompressed files" choice always
produced 16-bit PCM audio irrespective of chosen options.
* MP3 export usually produced a 128 kbps constant bit rate file
irrespective of chosen options; reported length often
incorrect
* MP3 ID3 Genre tag misread on import if the genre list in
Metadata Editor was opened and saved
* Exported metadata tags in MP3, OGG and FLAC often not seen by
player software - now substantially improved
* WMA exports (via FFmpeg)corrupted if metadata tags included
* Some multi-channel recording devices that previously recorded
more than two channels no longer did so
* Generated audio did not fit in window
* No warning was given when saving an empty project
* Beep on completing longer process did not work on many
systems
* fixed crashes importing lists of files (.LOF), in Meter Toolbar
and Change Speed

Platform-specific Bug Fixes:
* Windows Vista: crash opening Preferences with no sound
devices enabled and connected
* Mac OS X and Linux:
* Spurious clipping at start of playback
* Labels did not accept certain legal characters
* Shortcuts did not work after running effects
* Project Rate did not change to respect rate of first
imported file if that rate was unsupported
* Mac OS X only:
* Crash resizing project window
* Menu items became inactive or visibly corrupted
* File > Open dialogue did not always work on OS X 10.4
* Impossible to set independent Command and Control
shortcuts that shared the same key
* Freeze importing uncompressed files via On-Demand
(please report any remaining instances of this to:
[email protected])
* Portable settings were not picked up, instead settings
were taken from the default location
* Fixed unavailability of FFmpeg installer

New Features:
* F11 Full Screen mode
* High-quality "Sliding Time Scale/Pitch Shift" effect
* Audio Contrast Analyzer for testing audio on the
internet for WCAG2 accessibility compliance.
* Windows: sound devices can now be opened using the
more efficient DirectSound API

Other changes:
* Latency correction should be improved for many users
by employing a fixed rather than variable correction
* Grouping of Effects into categories turned off until
a way is added for users to do so themselves
* Numerous minor interface improvements such as Metadata
Editor navigation, new "hh:mm:ss + hundredths"
selection format
* Note: Windows users wanting to export MP3 files will
require the latest version of the LAME encoder from
http://lame.buanzo.com.ar/