Audio File - Phone Line (drifts in and out)

gisvpn used Ask the Experts™

I have an on-hold audio file which is played when we are waiting to join an online conference. The music is played down the phone line.

The problem I have is the audio file, which is just a regular MP3 file, sometimes cuts out while playing and I am not sure if this is because the file is not suitable to play on a phone line - it drifts in and out of the music, especially when the music is quieter.

Is there anything I can do to make the ranges of the music file suitable for a phone line or should it play ok? Wanted to ask for anyone's thoughts/opinions.
Watch Question

Do more with

Expert Office
EXPERT OFFICE® is a registered trademark of EXPERTS EXCHANGE®
Most Valuable Expert 2013
Regular .mp3s rarely work well over telephony for a lot of reasons but mainly because phone lines have a pretty restrictive frequency range (around 300Hz to 3kHz) which works fine if you're listening to speech at a fairly constant level but music has a habit of fading and then getting louder which phones don't like/can't cope with.  You're also already using a lossy format.

You're probably better using .WAV, and record in mono, 256 kb/s constant bit rate, 8kHz sampling and 32bit depth.

If that doesn't make a lot of sense, you can use free audio conversion software like Audacity to save your file with those settings.
Play it back through your PC headphones and you'll get an idea about how it will sound over a landline (mobile phones and hold music have their own issues because they incorporate clever noise-cancelling features to try to take out sounds that aren't speech)

You can also grab pre-made royalty-free samples to try out
this is one of many:

It's just the difference between playing the music over your audio system compared with the limitations of the phone-line filtering.


Hi MASQ - I played with the file in Audacity with the audio file and used the resample option and outputted as a WAV file in mono, I think it did improve the playback; appreciate the suggestions.

Do more with

Expert Office
Submit tech questions to Ask the Experts™ at any time to receive solutions, advice, and new ideas from leading industry professionals.

Start 7-Day Free Trial