SoundBible — free sound effects

soundBible-iconThe folks at SoundBible have collected hundreds of CreativeCommons licenses and public domain sound effects from around the web. The sound files are tagged with the license clearly displayed.

If we demand that our students obey copyright laws, then I believe we should make it easy for them to obey the law. SoundBible does just that.

The only downside is that the sound effects can be a little hard to find.

Bottom line: free sound effects for mutli-media projects.


Description: sound effects for students media projects, with clear licence reqirements.

License: CreativeCommons, public domain

Usefulness: possibly

Free Music Archive – legal music for your students’ projects (and yours, too!)

jjffjj Free Music Archive LogoObviously, many students steal music without a second-thought.  As educators, we can make them think twice by not accepting projects with stolen content.
And, by “think twice,” I mean teaching them about respect for artists.
But, it is not a reasonable requirement if permission is too hard to get or if royalties are more than a couple of bucks.jjffjj Free Music Archive Screenshot
Free Music Archive helps solve that problem because nearly all of the artists have given permission to use their songs non-commercially.   And, importantly, the music is usefully organized by genre and properly documented.
Free Music Archive is a service of WFMU, one of the great “open”  radio stations in America (another is KEXP who also contribute to this project).
With 63,000 songs, organized into 15  genres (including some specifically for video soundtracks) it is reasonable to require that students use legal music for their videos and multi-media presentations.   While licenses vary at FMI, nearly every song I surveyed had a Creative Commons license that would allow classroom use.

Tool:  Free Music Archive
Description:  Free music, mostly licensed for re-use.
License: mostly  Creative Commons
Alternatives: Audio archive at
Rating: very useful

The best FLAC compression level – a simple guide

FLAC is a great open source tool for archiving audio.   There is no loss in quality but it is smaller than WAV or AIFF files.   See my blog entry about the various audio file formats.

While FLAC is very easy to create and use, there is some confusion about the best compression level to use.   Unfortunately, a Google search does not clarify the issue.

For starters, it is important to understand that all FLAC files sound like the original.    That’s why it is called “lossless.”     The main difference in the compression levels is how much time it takes to “rip” the file and how small the resulting file will be.

Simply put – the higher compression level (6.7, 8): the smaller size of the file but the longer time it will take to rip.

Thanks to the good people at Stream #0,  we have some data to determine what compression level to use.   For their test, they used “Pride”  by U2  (3:50) as a sample song.


As you can see from the graph, a compression level of 4 or 5 is the best choice.  Higher takes longer but the file is minimally smaller.

Bottom line:   use compression level 5

See the original study.

Audio formats – which are best for a school library?

As I was writing the review on Audacity, it occurred to me that it might be helpful to have an entry on open audio formats.

Audio Files for Distribution

The vast majority of people use MP3s (endless players and software), AAC (Apple and Sony products; some phones) and sometimes WMA (Windows).




These are all effectively open-ethos formats although they are not truly open source. On my equipment, they all sound similar. (There are differences which are discussed at length elsewhere.)

In a library or school setting, MP3 files are the safe choice. All your users, no matter what software or players, should be able to play them.

The trick is to encode (aka “rip”) the file properly and, in my experience, you need just two compression levels (aka bitrates): one for spoken audio and one for music.

AudioFormats_encoding screen

For audio books and podcasts, I rip to mono, 64 kbps. This creates a small file and, to my ears, sounds fine.

For music, I rip to stereo, 192 kpbs. This creates a larger but still reasonably sized file and sounds good on my equipment.

I decided on these settings by encoding at different rates and playing it on my different equipment, including my best headphones and studio speakers. I compared the file sizes and made a subjective choice.

You may consider doing the same experiment on your equipment.

Keep in mind, if people are downloading your files, choose the smallest file that sounds OK to you. For me, 48 kbps is barely acceptable and 32 kbps is bad. Audiophiles and computer geeks will drive you crazy with their debates about the best audio format/codec. Bottom line: if it sounds good, it is good.

Unfortunately I can’t recommend the most common truly open-source audio format: OGG. It is a good format but it’s not widely adopted.

Audio Files for Archiving

For archiving, you’ll want a non-lossy, well-supported, format that can easily be converted to smaller, lossy, formats.

The safest choice is WAV, which is proprietary but open-ethos. Virtually every audio program can use a WAV file. Importantly a WAV can be converted to almost any other format and will be supported for many years. But, WAV files are huge.


Another good choice, especially for Apple users, is AIFF. Like WAV, AIFF is uncompressed, non-lossy audio. AIFF files are also huge. I suspect that AIFF files won’t be orphaned for a long time, although maybe sooner than WAVs. I am unclear on the license but it is open-ethos.

For years I have been archiving my audio in the open-source FLAC format. This is compressed but non-lossy. It is roughly 40% smaller than a WAV file but sounds the same. There are plenty of open source tools to convert FLACs to MP3s or burn to an audio CD. FLAC seems to be gaining popularity and I expect will be supported for a long time (but maybe not as long as WAV files.) I use the default settings on my encoding or exporting software.

(If you aren’t a purist archiver, a highest-level (320 kpbs) encoded MP3 should also be OK. These files will sound nearly as good as WAV/AIFF/FLAC and should be easily converted to any future file format. It will be much smaller than WAV or even FLAC.)

I tried to keep this simple but if you find this confusing, here’s what I do:

For distribution:

  • spoken word: MP3, mono, 64 kbps.
  • music: MP3, stereo, 192 kbps

For archiving:

  • FLAC, default settings

Audacity – digital audio editing

Few programs have dominated an open source category like Audacity.  It works so well that many people don’t even try other programs — especially for podcasts and “Powerpoints.”

Audacity can import or record multiple tracks, trim audio, level audio, fade-in and out, cut-out mistakes, etc — all the basic features you need for podcasts, radio spots, presentations, etc.   It has more audio-processing filters and the ability to add even more but I rarely use any of those.

It can export to WAV, WMA (Windows), AIFF (Apple), FLAC (cool) and most importantly, MP3.

Like  most open source software, Audacity is similar to programs from about ten years ago — but I consider this a virtue.   Modern programs can have so many features they they are a nuisance to learn.

A few years ago, I had a radio production studio with a couple of expensive commercial editing programs but I found Audacity to be the quickest for simple  productions — like two or three voices and a music track.

I challenged one of my technicians to produce a song with Audacity but he didn’t like it, saying it gave him timing problems.  (three or four musicians?).  More recently, I tried to use Audacity as a music sequencer and didn’t like it for that, either. I have also had problems with very long, single take, recordings (like over an hour.)

But, for simple audio production, it’s a very useful program, rivaling commercial products.  Highly recommended.

Tool: Audacity
Description: Cross-platform digital audio editor
License: GNU, free
Alternatives: Linux MultiMedia Studio, several others
Rating: very useful