[P1] Recording sound

[W.S. Higgins]

Jack Rodgers <jackrodgers at earthlink.net>

>On Thursday, January 30, 2003, at 07:27  AM, Peter Nacken wrote:
>> I was wondering if there is a simple app coming with the iBook that 
>> enables
>> me to record sound just via the little microphone that is built into 
>> the
>> screen frame ... I even checked the help file .. But no real answer 
>> there
>
>In 9 check the Sound control panel.
                                                                       
A better choice would be Simple Sound, which is an Apple product and
should be included with Macos 9.

The Sound control panel allows you to record "alert sounds," as Jack
suggests, but it appears to me to be limited to sound bites of 5
seconds or less.

Simple Sound allows you to record as much sound as your disk will
hold. It's not perfectly obvious how to use it, though.

1. Fire up Simple Sound.

2. Open the "Sound" menu and choose a sound-quality setting.  This
will make a BIG difference in how many kilobytes of disk space your
recording will use up.

If you want to make voice notes, choose "Phone Quality" or "Speech
Quality" and you will be able to make recordings many hours in length.  

If you want to make really high-quality recordings, your file will be
fat, and you should choose "Music Quality" or the ultra-high "CD
Quality."  (But if you need something this good, you probably
shouldn't be using the dinky built-in microphone anyway.)

3. Choose "New" from the File menu.

A control window resembling the buttons on a tape recorder appears,
along with "Cancel" and "Save" buttons.  The number of minutes of
"blank tape" available is also displayed, which is very handy.

4. Click on the "Record" button.  When you're done recording, hit
"Stop."

5. Hit "Save" and Simple Sound will prompt you for a filename in which
to save the recording.

Simple Sound can play this back.  It's also playable in Quicktime
Player and other sound programs.  You can convert it to different
sound formats (such as WAV or MP3) using various sound-manipulation
software, but Simple Sound doesn't offer any fancy options like that.
It's the bare-bones app that you requested.

I haven't explored sound recording in OS X.  Maybe there's a
comparable application on that side of the fence.  Anyone?

                                * * *


On the machine I'm using now, there are 380 MB available on the disk.
If I choose CD Quality and then File/New, I see I have 37 minutes of
recording time available.  If I cancel that, choose Phone Quality and
File/new, I see over 30 hours available!

The "quality" difference lies in how often the sound is sampled, and
maybe how many bits per sample are used.  I believe a CD is
16-bit-high samples at 44 kHz, or 44,000 times per second.  As you
know, this is enough data that it takes a whole silvery disk, about
660 MB worth, to hold 74 minutes of very-high-quality sound.
I don't know the technical specs on "Phone Quality" but I imagine
it samples at 8 kHz or maybe 6 kHz, and may use 7 or 8 bits per
sample.

I often use Speech Quality to record teleconference briefings from
NASA, and that's probably overkill-- Phone Quality might work fine.

Bill Higgins                           | "Treat your password like
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higgins at fnal.gov                       | six months."  --Cliff Stoll