1st topic

1^st topic

-------Forwarded Message from John de Szendeffy <[email protected]>-------

>In-Reply-To: <[email protected]>

>References: <[email protected]>

>From: John de Szendeffy <[email protected]>

>Subject: Re: #8321 Creating MP3s

>Date: Mon, 18 Sep 2006 09:36:41

>To: Language Learning and Technology International Information International

Information <[email protected]>

On Sep 15, 2006, at 11:38 AM, [email protected]

Wrote:

Language study at the University of Chicago is moving (fairly abruptly) into digital delivery.

I have captured audio from tapes as .wav files (40 kHz, 16- or 24-bit).

I want to convert these to mp3s files, but I find that iTunes (which I am using right now)

 gives me three Pre-set options and then I can customize as I choose.

Ø            Can anyone tell me what perceptible differences they have noticed among these

various options?

Good (128 kbps) and Higher (192) (both mono and 48 kHz) sound basically the same to me,

With a 13 MB difference in size for the same material.

Ø            What would 320 kbps get me? (Is there anyone out there doing phonetic

analysis of language audio?)

Barbara

ITunes allows you to extensively customize the conversion of imported audio.

Go to iTunes preferences, choose advanced and click on the importing tab.

You can customize the codec’s for MP3, AAC, WAV and others.

For digitized voice, such as textbook audio, we use MP3 encoding at a 48kbps mono bit

 rate and 22.050 kHz sample. To our ear, textbook audio thus encoded produces a very

small file that is indistinguishable from 128kbps (or higher) stereo with a sample

of 44.100 kHz.

John

John de Szendeffy

Multimedia Language Lab

Center for English Language and Orientation Programs

Boston University

890 Commonwealth Ave., 2nd floor

Boston, MA 02215  USA

ph                                         617.353.7957

fx                                          617.353.6195

Lab                                       http://www.bu.edu/celop/mll/

Personal                             http://people.bu.edu/johndesz/

"A Practical Guide to Using Computers in Language Teaching"

http://www.press.umich.edu/titleDetailDesc.do?id=97662

CELOP is accredited by the Commission on English Language Program Accreditation.

Accreditation by CEA signifies that an English language program or institution

has met nationally accepted standards of excellence.

Assures students and their sponsors that the English language instruction

and related services will be of the highest quality.

LLTI is a service of IALLT, the International Association for Language Learning (http://iallt.org/).

The Consortium for Language Teaching and Learning (http://www.languageconsortium.org/).

Join IALLT at http://iallt.org.

Otmar Foelsche, LLTI-Editor ([email protected])

My reason:

I interested to choose this topic because language studies at the University of Chicago

which have been developing into digital not only with computer, internet,

but also with audio.

First I read this article that has been wrote by Barbara.

I directly imagine and asked myself some questions:

Ø What the connection between created MP3, convert wav files into MP3 with language learning?

Ø How we can use audio to study language?

Ø Is it effective enough than using a computer or the internet?

Ø Is it acceptable or not by the teacher, the parents, and the students?

Then after I read the Accreditation article by CEA that signifies an English language

program or institution which has met nationally and accepted standards of excellence

and assures students and their sponsors that the English language instruction

and related services will be of the highest quality. I knew that whatever media we will be

use to learn and study a language it is not necessarily too important to use and applied,

but it is more on how we can prepare an effective way, the right method, and a better

service and instruction from time to time.

Not only related to why we can use audio to learn a language that make this topic

interested me, but also after I read this article, I got more knowledge about how I can get

a good MP3 sound, the way to convert wav to MP3, and how much the bit rate

that needed to make a good sound.

Also the software needed to convert and make the MP3 sound.

2^nd topic

At 11:38 AM 9/15/2006, Barbara wrote:

Good (128 kbps) and Higher (192) (both mono and 48 kHz) sound basically

the same to me, with a 13MB difference in size for the same material.

Ø            What would 320 kbps get me?

If you are recording voice, the difference in quality between 128 kbps

(the minimum for "CD quality), 256 kpbs, and 320 kpbs will be imperceptible

if you use regular computer speakers.

The difference in quality *may* be perceived when you play the files over

a PA system, for instance, or some other quality sound system.

If you are recording voice, then that's a different story.

There are certain instruments at certain frequencies which sonority

may be affected (i.e., decreased) at lower qualities. So a higher quality file

played in a high quality sound system will give you a better rendition of the music,

with all the little arrangements, additions, and "embellishments” that added

by the different instruments.

I'd say, if storage space is not an issue, use the highest quality (e.g., 256 or 320 kpbs).

You can easily use a "save as" function with the mp2 files to shrink them later if

Needed, but if you have the lower quality ones, and you want to increase the quality,

you'd have to go back to your original .wav files and does the conversion again.

Regards,

Roberto Perez

[email protected]

As Barbara mentioned, iTunes has three pre-set options, and a "Custom"

choice for MP3 encoding bit rates.

Which reveals about a dozen options?

It also offers the possibility of variable bit rate encoding.

An element in the decision of MP3 bit rate is whether you will preserve an

archive of the WAV files. If you archive the WAV files, then you could choose

 a fairly modest MP3 bit rate for the student listening files.

You will be able to produce a higher quality MP3 file (or whatever replaces MP3)

when needed. If you plan to dump the WAV files, and the MP3s

will be the archive, then you may want to record them at a higher bit rate.

I find 128 kbps to be perfectly acceptable to my ears for voice recording,

and we don't have student or teacher complaints for material recorded at that bit rate.

However, I record mostly at 160 kbps and 192 kbps, because I haven't had a space

shortage for storing the digital files. If I had to digitize our whole analog collection,

I would probably drop down to 128 kpbs. especially at the lower bit rates,

I would use the variable bit rate encoding option.

This option should offer better sound quality at the same average bit rate,

although I haven't done any listening tests.

Derek

Derek Roff

Language Learning Center

Ortega Hall 129, MSC03-2100

University of New Mexico

Albuquerque, NM 87131-0001

505/277-7368, fax 505/277-3885

Internet: [email protected]

Dear Barbara;

The IT folks at my new job suggest that sound files should be delivered

as true streaming audio.

In our case that is the QuickTime .mov format.

This allows dial-up users to get reasonable service.

I think that the larger file size would get you slower service

with very little perceptible quality.

It's like AM and FM radio. AM is fine for talk radio. For music FM is better.

Hard drive space is not really an issue any more, but bandwidth is.

For foreign language audio, streaming with Real or QuickTime is the way to go.

Best,

Karl Fisher

Lecturer in Spanish

NCCU

Durham, NC

My reason:

I chose this as my second topic is because this is the continuity from

my first topic, but it’s give me more detail about creating MP3 to aid us

to learn language. Creating an MP3 exactly has some ways to know more.

It not only needs good software, but also a good hardware too,

for example if we played a music file on the computer’s regular speaker

compare with PA system or other quality sound system, the difference

in sound quality may be perceived.So a higher quality file played

in a high quality sound system will give you a better rendition of the music.

Also if we just recording a voice, we must pay attention on what instruments

are around the voice we want to record. There are certain instruments

at certain frequencies which sonority may be affected (i.e., decreased) at

lower qualities. With all the little arrangements, additions, and "embellishments"

added by the different instruments, it all will affect the music rendition.

Also, we must pay attention to the music bit rate at how much kbps

(kilo bit per second) we must use to record and convert a music file to receive

a high quality music file.

Finally we must pay attention to the radio bandwidth if we use a radio to record

and listening music from another country and the compatible music software

to use, like Real or Quick Time.

PORTFOLIO

Hehen Cahyono