I'm hearing high pitched chirpy noises on 256k but not on 160k? what's up with that

I'm hearing high pitched chirpy noises on 256k but not on 160k? what's up with that

bum mp3s or bad speakers/earphones?

On different MP3s from different sources?

they all have the same song length.. it's a lo-fi band

it happens when the highest cymbals are played

what's the CD sound like?

it means you win the prize

it's cause 256k retains more of the high-frequency sounds, that's the advantage of encoding at a higher bitrate

Cymbals sound like water = shitty bitrate
Cymbals sound like birds = good bitrate?

is this the new album by Chirpy At 256, by any chance?

it's probably little birdy

Edith Piaf?

I rather not say who it is since it's pirated.. but the chirping is really annoying. I've decided to use some lower bit rate files for the mix cds I'm making. I've downloaded the same songs in 160 192 and 256 and I thoroughly believe that in the case of some lo-fi bands it is actually better to have the lower bitrate versions to counteract the highest pitch squealy noises.

Maybe I have dog-like hearing as well. It's my lame ass super power.

if it's a warbly noise that's maybe bad encoding (maybe even bad CD read?) rather than bitrate problem

Only mp3 decoding is a standard. The encoding is left to software engineers to do as they see fit. Different encoders will sometimes pick out very different sounds from the stream.

My understanding is that mp3 chops music into short "frames" and does a fourier transform on each, converting them from the time domain to the frequency domain. A lot of data space can be saved because in most musical sound, only a few frequencies are present at any given time, and for some "noisy" sounds like the crash of a cymbal, one frequency can represent a lot of nearby ones.

A lot of fine tuning goes into the algorithms for prioritizing frequencies and choosing which subset will be encoded in the mp3. One reason the LAME-encoder became the defacto standard for freeware/shareware mp3 encoding was because its output sounded more musical.

BUT, other encoders might just pick a cymbal crash and represent an important harmonic with a loud, isolated in the frequency domain, chirp, instead of a cloud of other cymbal crash harmonics.

Maybe the 256 you downloaded was actually (pointlessly) "up-sampled" from a low bitrate file or from a capture of a low quality stream?

^lol i thought the same thing

thanks everyone, I don't think so Jon

oh look who's now an expert

xpost - Thanks for that explanation Derelict. I too have dog-like hearing and compression (or digital clipping) tend to bug me. I especially hear it in the cymbals (probably because I'm a drummer).

The good news is that tends to keep me honest about downloading. I really do sample music for free and then buy the stuff I like because uncompressed sounds worlds better to me.

Well I might as well try to "up-sample" some low bit versions and see if I get the chirpy results

Also could be something that was originally wma but converted to mp3 with a shitty program...

Noise reduction to get rid of hiss etc can also leave chirpy artifacts.

Do you hear a chirping in this video?

https://www.youtube.com/watch?v=meQsklpNugI