An Experiment in Streaming Sound (2008)

I have noted that many websites are differentiating their audio streams into high fidelity stereo downloads for people with broadband and very low fidelity 24 kilobit per second monaural streams for people with dialup modems. I don't understand why dialup streaming is being done with such low quality. Most dialup accounts can stream at 29 kilobits per second. In Alaska, since 2003, all new phone company facilities have been required to support a minimum end-to-end data throughput of 28.8 kilobits per second 3 AAC 53.705(f)(1)(C). Most provide a connect rate of at least about 40 kilobits per second, so a 29 kilobit per second stream rate should be easily supported. That means it should be possible to provide dialup compatible stereo streams with fidelity that is certainly adequate for computer speakers. Here are some examples (original hi-fi mp3 obtained from musopen.com):

As you can hear, even the low bit rate MP3 stereo stream is perfectly listenable over computer speakers. And the low bit rate Ogg stream provides astonishingly good fidelity. The parameters I used for coding a 29 kilobit per second stereo stream compatible with dialup were:

About the streaming

The streaming here is actually pseudo-streaming. The links to streams are to *.M3U files (audio/x-mpegurl). These are simply lists of the MP3 (audio/mpeg) or OGG (audio/ogg) URLs. This allows the browser to instantly download the playlist and hand it off to an appropriate MP3 or OGG player that is capable of playing the file while downloading it. That only works without interruption if the bitrate of the file is less than or equal to the available internet connection bitrate. Pseudo-streaming works, but it is not the most efficient use of resources and it doesn't support cue/review. Like a radio broadcast, you have to listen from start to finish.

About the music

Finding music clips that can legally be used on a web page without obtaining prior written authorization, generally for a substantial fee, is really rather difficult. There is a lot of music with long-expired copyright and which is therefore public domain. But sound recordings of performances have a separate copyright, and very few of those have been donated to the public domain. For this test page, I used Jupiter, from the Planets, because (a) it is often performed independently of the whole; (b) it contains some percussion, which is important for any test of compressed music; (c) the music itself is old enough to be in the public domain; and (d) musopen.com offers it as an authorized recording that is freely reusable. The Wikipedia sound list identifies the recording as a performance by the Skidmore College Orchestra, and they have indeed made many recordings available to musopen.com for free use. Thus, it is to be hoped that the dreaded copyright police will leave me alone.


W. Gregg, An Experiment in Streaming Sound (2008) (w-gregg.juneau.ak.us/2008/text/2008f29-streaming).