Low pitched hum on recording


Sorry if this has been answered before but I couldnt find the exact response I was looking for (one that worked anyway).

I record from Skype using Pretty May for a podcast I do. I have found the following problem also happens when i just record myself directly with audacity so my guess is that it is a hardware issue.

Basically on any track that contains my input (eg either when I use Audacity directly or when I import from Pretty May and split the two people talking into separate tracks) i hear a low pitched hum behind my speech. It is clearly visible on the track as well. I can remove most of it using Noise Removal but it leaves my voice sounding slightly tinny.

I have removed all electrical appliances and anything I that thought may have been causing feedback or noise but it still happens. My friends input (eg the other track on a Pretty May recording) doesnt have any hint of this noise.

Could it be because I am using a laptop (Dell XPS maybe - not sure as its my girlfriends) and the headset is picking up the internal noises???

Its a problem that I have dealt with for 25 or so eps of my podcast but it starting to really annoy me having to always use the noise removal feature for my tracks but not my friends as it adds a lot of time to the editing process.

Any advice would be really appreciated.


How can we hear an example of this noise and are you in the US?


I am in the UK.

I can make a sample recording and not do the noise removal. Can I attach a file here though?

Unfortunately not. You will need to upload it to the internet somewhere and post a link.

Have you tried running your laptop from batteries? (Laptop power supplies sometimes cause interference)

Is there a place on your blog you can post a sample?


Thanks for the quick responses guys.

I’m at work at the moment but will sometime in the next 24 hours

a) try doing a recording without the lappy connected to the power (just using just the battery)

b) do a sample or samples of recoding so you guys can see what I mean by the humming noise. I’ll post links to the files and have them there as both mp3s and Audacity project files.

Thanks again in advance

A fifteen second piece with silent patches (hum only) will tell us a lot. If you’re in the UK and are having power problems, the interference will be a multiple of 50–your power frequency. If it’s not, then it could be anything digital.

Nobody can hear either 50 or 60 ( in the US). What you hear is the first and third harmonic. Here’s it’s 120 and 360. 400 (or 440) is widely considered to sound like the “middle” of the audio pitch range. This is why getting rid of it can affect the show pretty badly.

Describe the headset. Model numbers?


Thanks Koz and Steve

Ive just done some testing without the laptop connected to the power and it seems to remove the problem.

Doing the recording for my podcast tomorrow morning so once I edit it i’ll know for sure if it worked. If it didnt then I’ll record a sample of the problem and give u guys a link to it.

Thanks again