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Bob Rotheram :: Blog :: Technical considerations

July 24, 2008


Can you help?

The Sounds Good project has been about lecturers using digital audio to give students feedback on their coursework. Right from the beginning, one of my concerns has been to make things as simple, quick and convenient as possible for everyone – staff and students. Any obstacle is likely to put some people off, I reckon. So as we were getting ready for the project I assembled some technical tips and guidelines on digital audio, and we’ve been gathering experience as we’ve gone along. However, I know I’m an amateur when it comes to technical stuff. Can you help improve the advice that Sounds Good offers on using digital audio for feedback? Here’s the current list of bullet points.

• A handheld digital audio recorder will probably be more convenient than using a microphone connected to a computer.

• If you’re buying a handheld recorder, make sure it:

    - can record direct to MP3 (many can’t);

    - has a USB port, for easy upload to a computer.

• Two recorders meeting these specifications are the Edirol R-09HR and the Sony ICD-UX70. The Edirol is excellent – over-the-top for our purposes – but it’s not cheap (about £250). The Sony is adequate – with a cheap clip-on mike to avoid recording the noise of your hand on the controls – and costs a lot less (maybe £85 total).

• Check that your students can receive audio files. They will need access to a computer equipped with a sound card, speakers or headphones, and suitable software (e.g. Windows Media Player or QuickTime). Other potential obstacles include: firewalls (blocking certain types of file or email attachments); file size limits; full email inboxes; spam filters.

• To avoid some of these obstacles, upload the audio files to a place from where they can be retrieved easily. Then send links, not the files, to students. Maybe your university’s virtual learning environment is not the best place to store audio feedback files. [ANY SUGGESTIONS?]

• Try uploading a test file for each student before you attempt to give them real feedback. Ask for help if you meet problems you can’t solve.

• On the basis of this experience, give students further guidance (perhaps in writing) on how to receive and listen to audio feedback.

• Make sure your recordings are loud enough to be heard easily on a variety of equipment. The general advice is to set the recorder’s input level as high as possible without introducing distortion. Some experimentation may help.

• Make your audio files as small as possible, so they can be sent quickly and stored economically.

• Mono recording – giving files typically half the size of stereo – is likely to be adequate if only one person is speaking.

• MP3 is a very useful format: compact and widely-playable. An MP3 file is typically less than 10% of the size of a WAV file of similar quality and can be played on a broad range of devices, including the portable music players owned by many students.

• Aim for the minimum acceptable sound quality for the particular purpose. Speaking to an individual student will probably not require as high quality as feedback to a group or a podcast on a public website.

• 32kbps MP3 – which translates to about four minutes per megabyte – will probably be good enough for giving individual feedback to a student.

• Back up your files. Copy them all to at least one other device.

Comments and suggestions welcome!

(Posted by Bob Rotheram, Project Manager, Sounds Good)

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Posted by Bob Rotheram


  1. Re: "send links, not files"

    I'm using media streaming. That is I can store my media files in an area on the media server at Leeds University. The files can then be accessed via links that open in Media Player. However, these cannot be downloaded - so these are not podcasts, just audio files.


    Kathrin KaufholdKathrin Kaufhold on Friday, 25 July 2008, 16:22 BST # |

  2. Thanks for the tip, Kathrin.


    Bob RotheramBob Rotheram on Monday, 28 July 2008, 10:45 BST # |

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