Audacity Forum

Any ideas about creating podcasts? The audio-technician in our church tapes the message then reproduces it as an MP3. So far so good.

The job then is to edit it on Audacity, then load it up as a podcast to the website. We are advised that, since MP3's lose quality when edited/re-compressed etc, we should start with a high quality file. OK, so Mike (our audio-tech) supplied it in stereo 44 kHz 64 bit and here it is reduced to stereo 22 kHz 16 bit.

The problem is that it sounds odd and is showing up every little background noise etc. I'm inclined to think that the rules for recording high quality music is different to the rules for speech. What I'm asking is this: What is a practical starting point for this kind of file and also, would mono be more appropriate than stereo?

Gideon

Podcasts are often done in mono as better quality sound can be achieved for a given bit rate than for stereo.

All the recording and editing should be done in WAV format. 44.1kHz 16 bit will probably be sufficiently high quality.
You would Export an MP3 version of your show as the final step in the production.

The simplest way to host a podcast is simply to upload the MP3 to your web space and provide a link on your website to the MP3.
There are various other more complicated ways that provide additional features (Google for "Podcast").

There is a tutorial about making podcasts on the Audacity wiki http://wiki.audacityteam.org/index.php? ... h_Audacity

Your recording is highly distorted by compression artefacts,
(I have attached an “before & after” example of this phenomenon as an mp3 in zip file).

My suggestions to improve the podcast …

1. Convert the original stereo 44000Hz recording into a mono 22050Hz version.
The “Tracks” menu in Audacity 1.3 has “Stereo to mono” and “resample” (to 22050).
If the original recording is higher than 16bit depth (you say 64bit) then convert your podcast recording to 16bit depth.

2. "Save as type mp3” with a bitrate no lower than 32 Kbps. (Kilobits per second), see "options" when saving as mp3 to set bitrate.
(the "before" countdown part of the attached mp3 is 64Kbps 22050hz 16bit)

NB: your podcast host may be applying additional compression to the recordings you supply them to minimise the resources necessary transmit it,
which will increase the amount of compression artefacts (distortion) in the broadcast. Not much you can do about that other than find a new host.

3 (Optional). The sound of the speaker inhaling after each sentence is conspicuous. The speaker should have the microphone further from their mouth,
fitting a (homemade) pop-filter would help keep them from getting too close to the microphone.