I have recorded some hold music from a telephone call using the headphone out jack from my smartphone, running to the line-in of my Focusrite audio interface and from there to Audacity running on the computer.

The sound quality is pretty low, with some low-volume crackles every now and then and a volume way too low.

I post-processed the recording in Audacity by normalizing the audio and running the noise reduction filter, but I hope there is something else that can be done.

Is there any way I can improve the quality of the source material (i.e. how can I record the music from a telephone call better)?

How should I post-process the recording to maximize the quality?

  • Forensically, yes, you can improve sound quality to some degree, but not much with free software. If you're just doing this to save 99p on iTunes I really wouldn't bother. If you're trying to learn forensic/archive restoration/recovery techniques & are willing to shell out on some proper software eventually [budget $2,000 at a guess], maybe we can help. If the latter, add details to your question & post the track at its current 'full' quality on somewhere like SoundCloud. – Tetsujin Aug 22 '19 at 16:52
  • The source is telephone quality (so 8 bit sampling at ~8 kHz, no sound reproduced above ~4 kHz, with aggressive compression). Generally, you can't add what wasn't there in the original. – Hobbes Aug 22 '19 at 18:29
  • There's really nothing you can do here. The processing chain of a standard telephone call is really rubbish and designed entirely around maximizing voice intelligibility over a very limited transmission bandwidth. Nothing at all to do with quality. Most of the useful information in the music will be gone by the time it reaches your software. Your best bet is to play what's left into shazam and then locate the original track online. – Mark Aug 23 '19 at 0:00
  • Ok, thank you all for the comments. The piece of music is not available commercially, that's why I have resorted to this method. It is just for private use and as a backing track for jamming. – simon Aug 23 '19 at 8:23
  • It's probably Library music then - which is available commercially, you just have to know where to look. Start at deWolfe or AudioNetwork - if they don't have the exact track, they'll have something similar. You can actually use it for yourself at home without having to pay for it - you pay to "use" it commercially, if you don't do that, then technically there's no usage fee. – Tetsujin Aug 23 '19 at 13:24

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.