Can podcast MP3s be made louder?

February 8, 2008 6:17 AM

Can MP3 files be processed to increase their volume level and make them louder? If so, with what and how?

I spend a lot of time in cabs and on airplanes travelling for business and one of the ways I like to use this otherwise mostly dead time is to listen to Podcasts of NPR's Fresh Air on my iPod. In very loud cabs and on most airplanes, however, they can be very difficult to hear even at high volumes. I don't have this problem with a lot of music files for some reason.

I'm wondering if there is some process I can put these files through using something like Audacity or other audio manipulation software to increase the volume level of the file and make them easier to listen to in these noisy environments.

posted by hwestiii to technology (16 comments total)

Yes, you can do that in Audacity. There's an AMPLIFY tool sitting right there.
posted by Wolfdog at 6:21 AM on February 8, 2008

I believe you can also do this in iTunes if you use it, under one of the info tabs, you can set a higher volume level for the track.
posted by OmieWise at 6:24 AM on February 8, 2008

Dynamic compression.
posted by IronLizard at 6:27 AM on February 8, 2008

Its not the most stylish option, but a better answer might be to invest in some quality headphones that cover your entire ear (assuming you are now using the standard "earbud" style). Its better (in the long run) for the health of your hearing, and saves having to further tweak the already lossy mp3 format of your files.
posted by jmnugent at 6:28 AM on February 8, 2008

MP3Gain.
posted by futility closet at 6:31 AM on February 8, 2008 [1 favorite has favorites]

i know this is not what you asked about but perhaps you should look into buying better earphones. most mp3s have a max volume so that you do not permanently damage your ears.
posted by phil at 6:32 AM on February 8, 2008

I second Phil. You'd do better by purchasing a set of noise isolating/canceling headphones.
posted by pmbuko at 6:44 AM on February 8, 2008

A) Turn on the Sound Check in iTunes & your iPod. This will normalize the volume of all your music to the same level.

B) Check your iPod settings and make sure that your Volume Limit is turned all the way up.

C) Select the track(s) you want to increase the volume of in iTunes, choose File > Get Info and turn up the Volume Adjustment as high as you like.
posted by designbot at 7:14 AM on February 8, 2008 [1 favorite has favorites]

Also, did you happen to purchase your iPod in Europe? There are hard software limits on the volume for EU (including UK) bought iPods. It's especially harsh with the newest refresh of the line. Luckily for me, I tend to listen to stuff quietly, but it's disconcerting to have the volume bar so high up.

Anyway, at the current time, there's no way to override this behaviour.
posted by Magnakai at 7:26 AM on February 8, 2008

MP# Surgeon does a lot more than just normalizing, but it is very very fast, totally reliable, and it supports batch commands.
posted by La Cieca at 8:42 AM on February 8, 2008

While mp3 volume can be increased as other answers address, I'd second the recommendation for investing in better headphones. A decent pair of sound-isolating in-ear 'phones (I love my pair of Shure e2c's but there's plenty of options) provides a huge listening difference compared to things like the stock earbuds that come packaged with players. Much clearer sound, and you can do things like listen on airplane flights without cranking volumes to levels that'd make any audiologist scowl disapprovingly at you about.
posted by Drastic at 9:23 AM on February 8, 2008

Just want to 'nth the recommendations for better headphones or using normalization over amplifying. The problem with amplifying is you'll need to stay below volume peaks otherwise you'll get a lot of distortion artifacts. In your case normalization should be pretty much the same as amplifying (as it's going to bump the volume up in roughly the same way) but the philosophy behind the term normalization is slightly different as it attempts to bring all of your audio files to the same volume levels, as well as tighten up the volume variance a bit so the sound does not get distorted.
posted by samsara at 10:19 AM on February 8, 2008

Also, instead of reencoding every mp3 you have, most mp3 players today have an equilizer, if you boost all the levels up, you'll get what you're looking for. on itunes and winamp specifically, when you go into the EQ, theres a bar on the side thats just 'gain'. pop that one up and everything gets louder.
posted by Mach5 at 10:26 AM on February 8, 2008

You're getting this problem because most music these days is very highly compressed -- that is, the quiet bits are not much quieter than the loud bits. This makes things sound louder. It also reduces the contrast between the loud and quiet parts, which is part of the listening experience, so audiophiles hate it.

Public radio is not heavily compressed, as a general rule. This is in contrast, often, to AM talk, which often is compressed twice by the time it hits your radio. It's definitely in contrast to FM music programming, where super-compressed radio versions of songs (they try to make them louder so they'll stand out) are compressed further by stations (who want to be the loudest station for the same reason).

Not compressing makes it seem quieter, but it also is less tiring for your ears. Ears tend to sort of automatically turn down the volume on stuff that's heavily compressed.

So... you can either open everything up in audacity and compress it further, which will almost certainly make it sound worse (not least because you'll be re-encoding the MP3, and thus getting a degraded version of a degraded version of the original show)... or you can get better headphones. I recommend the latter.
posted by YoungAmerican at 5:46 PM on February 8, 2008

MP3Gain is the way to go, without losing sound quality.

Otherwise, yeah, get noise-cancelling headphones. Airplanes are pretty noisy.
posted by neckro23 at 9:42 PM on February 8, 2008

nth-ing the get better earphones crowd. I bought a set of Shure E2c eaprhones (now out of production) and with the foam sleeves, isolation is great and I need about 1/4 the volume I used to have to use on the plane etc.

Protect your hearing.
posted by arcticseal at 5:59 AM on February 9, 2008