Monday, June 30, 2008

Audio Recording Tips

I've recently been working on some audio recording and editing for training modules; it's a learning curve to get it right so I wanted to keep a record of some points that are important to the process. This post is more of a reminder to myself more than anything else. Some of these actions I already had well in hand and some are as a result of the 'experience'.

Before You Start:
  • Write a script. I simply do this in Word using a table, with a new row for each recording. My final output in most cases will be using PowerPoint and then converting via Articulate so each row also represents a slide. Keep the sections reasonable in length so that mistakes can easily be re-recorded and the file size kept manageable.

  • If the voice over 'artist' is not yourself and they are not recording directly into Articulate, it's a good idea to have the following details for each slide;

    - Slide #
    - Slide Title
    - Description of visuals on the slide (this helps the person recording to match the audio with the visuals - particularly if the visual content is not finalised or they are in another location)
    - tick box they can use to help them keep track of where they are up to
    - audio track name or number (If they don't have time to do this, you can make a note on the document as you edit each track)

  • Use paragraphs to separate the content in longer slides; make the formatting simple and easy to read (I use Arial). It's also important to be clear what is to be read, for instance, don't use numbered bullet points unless you want the person to read the numbers out loud. Be careful how your format numbers and statistics; think about how the text will be interpreted.

  • The script can then be used for the 'Notes' view if using Articulate or similar applications

  • Provide some basic instructions about recording;

    - quiet place to record
    - how to use the script
    - type of microphone
    - how to avoid pops, hisses and background noise (pop shield?)

Equipment:

  • You don't have to spend a lot of money to get the job done but a decent microphone is a must. Forget headsets and go for a desktop as this gives a more even balance and better control over breath sounds and pops and clicks.

  • You'll also want to avoid plugging your mic directly into the mic input at the front of your computer in most cases as this picks up internal noise from the machine. Best to look for a USB option for easy use. Many of these are Plug & Play, no installation software required (of course, you'll need software to record and edit your audio). Often, they'll be labelled as ideal for podcasting.

  • If your budget is minimal, a Logitech desktop noise cancelling mic will do the job. If you can afford to splash out a little, there are plenty of mics specifically designed for podcasting which will do the trick. From my research (and because it is so cool) I choose a Blue Snowball USB microphone. The best price I found was through B&H Photographic supplies. I had ordered a portable green screen from them before so already had an account, and their service is just excellent; delivery from US to Australia under a week and that included a weekend. Price? $99US (It now also has a sibling - The Snowflake - which has been designed for portability and is around $60 US)

  • The Boagworld lads and The Rissington Podcast Chappies both recommend the Samson C01U mic. The Blue website has some great comparative 3rd party reviews on the main USB mics in the market and these can help you decide which is best for your purposes.

  • If popping noises are a problem or lots of people will be using the same microphone, you might want to invest in a pop shield or pop filter. This simply sits in front of the mic and 'shields' it. For the budget conscious, try some stocking stretched over a piece of coat hanger wire, otherwise you're looking at around $25 US.

  • A quiet room may be all you need however I came across a brilliant portable solution developed by well known US voiceover artist Harlan Hogan. It's so simple, it's genius! Take one collapsible fabric storage cube and a sheet of acoustic foam cut into tiles that slip inside the cube, place your mic inside the cube and voila! a portable recording booth. Harlan can supply these ready made, but really, it's too easy. I'm quite sure other foam would do but acoustic foam is designed to absorb sound so is the recommended option.

    Update: I created one of these in under 20mins. The portable cube came from Kmart ($7) and the acoustic foam from Clark Rubber ($35 for an offcut with plenty left over, almost enough for a second cube). After a few minutes testing, I was impressed; all the background noise is blocked out and the voice audio is beautifully clear and crisp. You'll have much less editing to do with such a set up. You can see some photos of my portabooth on Flickr.

  • Software? If your wallet is overflowing there are heaps of specialised programs to help you record and edit, or add special effects, fades etc. Adobe offers both Audition (high end professional use formerly Cool Edit Pro) or Soundbooth but many people do just fine with free software such as the well-known and loved Audacity. Myself, I prefer the free version of WavePad over Audacity. I just find it 'nicer' to use, and easier to really get into the waveform of each track and do some fine tuning. I'm currently investigating Soundbooth though and will let you know what I think.

  • Another freebie to add to your toolbox is The Levelator; this strange piece of software apparently does amazing things, particularly if you have more than one speaker. Simply drop your audio file onto the program icon and it does its thing.

How to Speak:

  • This is where the script is vital. You can practice beforehand but also if you need to record again to 'fix' a section, it's easy to cut and splice separate tracks if the content is identical; ad lib would make it much harder.

  • If you stumble - stop and then repeat that small piece and keep going; it's easy enough to cut out such mistakes. Or, by keeping the slide content of a reasonable length, it can be re-recorded if it's a real mess up.

  • Try to avoid taking great gasping breaths; these can be edited out but just be aware of their impact. The same with pops and clicks etc. Pops are evident on 'p' words or sudden pushes of air from your mouth. The trick is to try and keep things as even as possible. Also be aware of extended 'f' and 's' and 'k' sounds. You can use your editing program to shorten these to reduce the impact but it's better if they aren't there in the first place.

  • Leave a few seconds silence at the start of each track - or insert this using your software. This gives a slight 'rest' before the slide loads and the audio starts but is also useful if you output to say, podcast format - each track then doesn't run into each other but sounds more natural.

  • When you are speaking, use a lower tone than normal, speak slower and have a smile on your face. The smile brightens the tone, makes you sound crisper and more friendly. Imagine you're talking to a friend across the table. Listen to yourself and take note of words that you might tend to 'twang', lisp or rush. Practice these until you are happy with the output.

  • Don't read in a monotone manner but on the other don't make it sound like Children's Story Hour; you want to sound interested and appropriate for the topic

WavePad Settings:

  • The tracks I recently edited were quite 'hissy' with lots of background. I got them practically perfect with the following filters in Wave Pad, in this order:

    - Normalise > Normal
    - Noise Reduction > Multi-Band Noise Gating (the better quality option introduces strange background distortion which this option does not)
    - Equalizer > High Pass (default settings)

My Snowball mic has arrived in the mail today so I'm sure I will have lots of other tips to add soon!

9 comments:

SSneg said...

Great entry, many thanks!

Anonymous said...

This is exactly what I was looking for...laying out how to go about "Recording" for our eLearning. Thank you!!!

Abhishek said...

thanks a ton!
very very helpful!

Travis Smith said...

What did you find out about Adobe Soundbooth?

retrogrrl said...

Hi all - so glad you have found this post useful!

Travis - I had a quick play with Soundbooth and, for the work I do, didn't find it that much different to Audacity or the free version of WavePad. I prefer WavePad's interface (it just feels more comfortable to use) and believe it's equal to Audacity in functionality.

If you are using Articulate, it does have an audio editor built in but it's quite basic and doesn't offer much in the way of noise clean up etc

cheers!

Wendy

Carolyn said...

Do you mind if I re-posted this topic of your blog?

Anonymous said...

I used many parts of your article!
Thanks!

But i disagree with Audio filters.
i use them in this order:
(your methods adds a subtle hiss to the sound for me).

1- Remove unwanted parts such as hiss, etc.

2- Record 5 seconds of complete silence, then select that part, then go to Effects > Noise Reduction > Grab Noise Samples from Selected Area and then go the same way and press "Apply Spectral Subtraction Based on Noise Sample" and you will see much better result that is smart.

3- Simply use the Levelator software at:
http://www.conversationsnetwork.org/levelator

I don't like using other tools when there are ready filters, but when i tested it, there was a noticeable difference between Levelator and other filters such as Normalize, Equalizer, Amplify, etc.

Thanks.

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Amy cathern said...

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