Wikipedia:WikiProject Spoken Wikipedia/Recording guidelines

From Wikipedia, the free encyclopedia

[edit] Production notes

Ogg Vorbis audio is the format to use. We recommend that you use the following settings: 48 kbit/s, 44.1 kHz mono. In many audio editing programs this can be achieved by setting the encoding "quality" to minimum when making an Ogg Vorbis file from your recording.
The resulting filename should consist of the article title in canonicalized form plus the ogg extension. If you upload it to the Commons, the title must be prefixed by "en-".
Treat links like text when reading. Any vocal indication of every link would disrupt the flow. However, you are free to pick out the most relevant links and mention them at the end.
Speak more slowly than normal, by about 25%. You should have about 150–160 words per minute so people can comfortably hear an article. Most conversational speech is at 200 words per minute or more. [1]
Tell people where it's from. Begin your recordings with:

"Article name, from Wikipedia, the free encyclopedia, at E N dot wikipedia dot org." and end each one with "This sound file and all text in the article are licensed under the GNU Free Documentation License, available at www.gnu.org/copyleft/fdl.html" (GNU is pronounced /gnu/ (help·info) ("g'noo") or can be spelled out).
As you come to them, read out all headings like this "Section one: History", "Section two: Modern uses" etc.

[edit] Production tips

Warm up. The vagaries of the day can leave your vocal chords clogged, especially if you have recently been eating or drinking milk-based foods such as cheese and chocolate. Some gentle humming before starting to record can cleanse and moisten the vocal chords leading to a better sound to the voice. Take a look at Vocal warm up if you want more ideas.
Stay relaxed. Whenever you realize that your voice is becoming tenser than normal, or you're having more and more trouble speaking fluently, take a break, and resume when you feel muscular tension going away. Keep some fresh (not cold) water in reach, and drink some whenever you feel your mouth drying out. Also, speak outward, with your chin up. Posture and facial expressions can affect voice recordings.
Try standing up. If you think your voice sounds a little thin or lacking in expression, standing while recording might help. Radio announcers and actors regularly stand while speaking to lend additional depth and confidence to their performance.
Speak across the microphone or to the side of it, rather than directly into it, to avoid pops and breath noise. A distance of several centimetres away from the microphone is recommended.

Another method of reducing pops and breath noises is to make a homemade screen. Form a circle with a coat hanger, cover it with an old pair of tights/pantyhose, and speak through it into the microphone.
Volume levels — make sure your audio levels are high but not clipping and, if you can, compress and normalize your audio.
For those unfamiliar with "audio" terminology, a brief description of these terms:
- Compression is a dynamic levelling of audio, making loud parts quieter, and the quiet parts louder, so that a consistent sound level is achieved (on professional audio gear where 0 dB is maximum, −12 dB is a good place to level the average RMS for speech). Beware of excessive compression, as it will make noise stand out (even after noise reduction) and could exaggerate some sounds of speech.
- Normalization is a calculated adjusting of audio so that the loudest peak is set to maximum potential volume, generally it is close to 0 dB (on professional audio gear where 0 dB is maximum, −10 dB is a good place to normalize the average RMS for speech).
- RMS — see Audio power
Mess up a take? — Instead of stopping the recording, just stop speaking, then speak out "three, two, one" and then start reading again. You can easily edit out the "flub" since the countdown gives you a cue on where to make the edit, and gives you some "silence" to edit in.

[edit] Removing noise

You should remove background noise from all your recordings. Here is a guide to doing this in Audacity.

Make your recording.
Select a chunk of the recording where you were not speaking. You should see a slight bumpiness on the line, representing the background noise.
Select Effect → Noise Removal → Step 1 → Get Noise Profile.
Select the entire recording (Ctrl+a).
Go to Effect → Noise Removal → Step 2.
Drag the slider a little to the left, towards Less.
Select Remove Noise.

The reason for moving the slider is that the default setting is rather powerful, and is likely to affect the sound quality by removing too much noise. When in doubt, remove too little rather than (irreversibly) removing too much. A clue that you might have removed too much noise is hearing "bubbles" ("speaking in a glass"-like sounds) in the recording.

Even at the lowest setting, this tool should remove all audible background buzz. If it is not able to deal with the background noise, then you probably need to record it again, this time without buses and motorbikes going by your window!

If all this seems like a lot of hassle, then send a message to a fellow contributor (such as User:Mdd4696) and they'll do it for you.

[edit] Sound levels

You should be adjusting the recording volume so that the peaks you see on the screen do not touch the top and bottom when you speak. If they do, then "clipping" will occur (part of the sound information will be lost) and you'll just get a blaring noise. On the other hand, the volume should be set fairly high.

Once you have finished the recording, you should boost its volume. If you perform normalization as described above, the volume will increase. Normalization will amplify the signal as much as possible without causing "clipping". If normalization does nothing, then the software can't boost your voice without clipping. In this case, the chances are that you set the recording volume too high. It is also possible that there is a peak at some point in the recording because you made a loud noise (common culprits are: shouting the first few words of a sentence; coughing; clicking the tongue; choking on food; scraping your chairlegs on the ground...). You should try to edit that out, or perhaps just have another try.

It is also possible to select individual parts of your recording and boost them separately. However, compression (part of the "Dynamics Processing" effect in Adobe Audition) does this automatically and dynamically on a far finer scale. Compression is preferable.

[edit] Recommended tools

Use audio recording software that can record section by section, like:

Audacity (open source, for Mac, Windows and Linux [2])

For information on how to configure your file to fit the Recording Guidelines using Audacity, see this short guide.

Sony's Sound Forge
Adobe Audition (formerly Cool Edit)
GoldWave ([3])
GarageBand (part of iLife, Mac-only)

[edit] Sample configurations

Alkivar – Custom built PC, Win XP, Dual AMD Opteron (overclocked), Sony's Sound Forge, RØDE NTK ($495).
Andrevan – Custom-built PC, Windows XP, Pentium 4 2.4 GHz, 512 MB RAM, SoundBlaster Live! Value, generic Dell microphone, Audacity.
Anas Salloum – Custom-built PC, Windows XP, Athlon 64 3200+, 1.0 GB RAM, SoundBlaster Live!, $6 microphone, Audacity.
blankfaze – eMachines PC, Windows XP, 1.3 GHz, 256 MB RAM, some old microphone I've had since about 1997, Audacity.
brian0918 – Custom-built PC, Windows XP, Audacity, Logitech USB microphone
Ckamaeleon — Gateway desktop ca. 2000: 800 mHz, 256 MB RAM, Ubuntu Linux, Audacity (ALSA), generic OEM mic.
Darobsta - Toshiba Satellite L10 Laptop, Windows XP Pro, SM58 microphone, CoolEdit Pro 2.0, Technics RP-F300 stereo headphones
Demi – Dell Latitude laptop, $11 microphone, OpenBSD. Using sox and oggenc.
DO'Neil – PC running Windows XP, Audacity, recordings done with a cheap Verbatim headset microphone.
Fuzheado – Apple iBook G4 1 GHz, MacOS 10.3.8, Audacity, built-in microphone
GDallimore – HP PC, various NCH Swift Sound software products, Shure PG81 microphone connected via an M-Audio "Solo" Firewire Audio Interface.
Luigi30 – PC running Windows XP. Recording with GoldWave to either high or low bitrate Ogg Vorbis depending on length, and using a headset microphone.
Rfc1394 – Hewlett-Packard a305w running Windows XP home with noname generic $6.00 microphone, built-in sound card and Audacity.
silsor – home-built Athlon PC with cheap ES1371 sound card, Audacity/ALSA/Debian (all free software), $3 microphone. If I can do it so can you!
Tmalmjursson – Dell Optiplex GX260, running Linux (Mandriva) With Audacity Version 1.2.4, £19 Headset Mic (Trust), Onboard Sound (Intel 82801 Chipset) - Total cost: £1300
Troythompson – home-built Athlon PC, Windows XP, Audacity, Plantronics series headset (about $40 USD).
Trevor Caira – Dell Dimension T500 with an emu10k1, Slackware Linux 10.1.0 ALSA, ecasound, oggenc, LADSPA, Shure SM57, Behringer Eurorack
mrdallaway – Apple Mini, MacOS Tiger, Audacity, iSight microphone
MykReeve – Apple PowerBook G4 1.33 GHz, MacOS 10.3.9, Audacity, built-in microphone
User:Cluth – Apple PowerBook G4 1.67 GHz, MacOS 10.4.5, Audacity/Logic Pro/Soundtrack Pro, Shure SM7B, Mackie Onyx 1220 with FireWire card (I'm a broadcast journalism student and independent radio producer)
Linuxbeak – home-built Pentium 4 based PC running Gentoo Linux. Audacity, ALSA, Soundblaster Audigy card with a generic microphone.
SatCam – Dell PC running Windows 2000 Pro. Using Audacity with a Shure SM7B ($350) (Behringer mixer for preamp)
Pbeesley1989 – HP Pavilion DV1000 Laptop running Windows XP Professional. Using a Creative Technology HS-400 headset (around £20) and Audacity.
Peter McGinley – Custom built Pentium 4 2.6GHz PC running Windows XP. Using an Altec Lansing AHS-502i headset and Audacity.
Cchan199206 Using a Dell PC, with a $25 logitech headset and Audacity. And a SBLive! 5.1.
NEX2NUN Apple iBook G4 (1.33 GHz), Mac OS X (Version 10.4.7), Audacity, M-Audio MobilePre USB (preamp), Shure 8900 mic (w/"pop screen")
Veratien – Packard Bell A8550 dual booting Debian Sarge and Windows XP. Recording onto external USB storage using an AKG C3000B through a Behringer Eurodesk MX2442A into an external EM-U 1616M DSP. Mastered using Audacity on both machines and operating systems. Total cost: ~£2200 (I'm a Music Composition student.)

[edit] Sample encoding script

DanielHolth uses this text as a shell script to encode and tag his spoken articles:

#!/bin/sh
oggenc -q0 $1 -c "copying=Licensed under the GNU Free Documentation License:  http://www.fsf.org/licensing/licenses/fdl.txt" -c "article=$2" \
-c source="From Wikipedia, the free encyclopedia: www.wikipedia.org" \
-c "version=`date`" -c performer="Daniel Holth, http://en.wikipedia.org/wiki/User:DanielHolth, <dholth@fastmail.fm>"

After calling the script "encode.sh", encode.sh wavefile.wav "articleurl" encodes and tags the spoken article.