Audio formats for telephone switchboards

Many of our customers do not know the difference between the various audio formats for telephone switchboards; that may not seem to be a problem, but if you have a company with a switchboard or voicemail you will know how important this aspect is. So, here is a short article explaining the various differences.

The most common audio formats for switchboards and voicemails are MP3 or WAV.

MP3 format
The MP3 format is the most widespread compressed format, exploiting human imperfections by eliminating the frequencies that hearing cannot perceive. This format allows a size reduction of up to 90% and is very useful in all those cases where we want to listen to an audio message with good quality. This is the most accurate format accepted in the field of telephone switchboards.

WAV format
The WAV format stores acquired samples directly; normally it uses no compression and is often the heaviest and highest quality format.
Given the theory, we have to say that unfortunately this is not so in the PBX area, where the WAV format is the one most accepted, but only after due frequency compression; this makes it qualitatively less accurate than the MP3 format. It should be noted that this compression is done on the request of switchboard manufacturers and we are not responsible.

The most common compression formats that occur through audio codecs for the WAV format are:ALAW, ULAW and PCM (usually the most accepted).

It must also be said that loading a high quality audio format in a switchboard is useless because, during calls, the band that the provider assigns for the audio stream is very low. This is due to the technical infrastructure built with old components; bear in mind that most calls still pass through copper cables dating back to the 90s.

The world of audio is vast and we can find additional formats such as Flac, Ogg, Aac, M4a, M3u, Pls, etc., but they are not part of the world of telephony and telephone switchboards. Furthermore, we apologise to all audio experts if we have not gone into detail talking about frequencies or bit depth in this article.

TelephoneVox produces all the audio formats you need for your switchboards and voicemails: in the event that what you are interested in is not present by default on our website, you can select “other” and specify what you want.

If you have doubts about the audio format accepted by your switchboard or voicemail, you can write to us at [email protected]

[email protected]