Version 2.0 reviewed by Darrin Koltow - 04/10/00

User Interface

Even from first glance, Digital Ear's "face" is clean and very friendly. All of the controls on the main window are large for easily manipulation; the model of the piano keys has nuanced shadings that make it look much more realistic than its counterparts in similar apps; and every button has a immediately recognizable icon.

Consuming the biggest portion of visual real estate in the main window is the Voice Features Display (VFD). Use this display to work with MIDI data that's been converted from a Wave file. The VFD shows you four aspects of each MIDI note: Pitch, Volume, Brightness, and Note On. Each of these is color coded and changeable, independently of the others. Included here is the ability to delete Note Ons. A problem with this is that you're not asked to confirm the deletion and there is no undo feature: once a note is gone, it's truly gone.

Working with the VFD and its associated Editor is pretty easy; you can freely select any of the Note Ons, and change its brightness, volume, and octave. In particular, as you move the octave control you can see the note pitch change immediately on the VFD. The ability to select a group of Note Ons, and increase the volume on all of them at once, for example, isn't there; but a sequencing app is more appropriate for this work anyway.

The help is extensive, friendly, and helps you begin converting Waves to MIDI files immediately with a quick start section. Help is in an HTML file, which somehow seems easier to use than the standard help system found in other apps. Despite the misspellings in the file, the document is well laid out and organized, with an abundance of friendly, full-color graphics that you seldom find in the standard help system. Also, online support from the Web site is fast and friendly.

While beginning audio to MIDI users will find the user interface easy to work with, you might feel frustrated at the lack of keyboard shortcuts, as you use Digital Ear on a regular basis. For example, a shortcut key to start the Wave-to-MIDI conversion would be convenient. And the ubiquitous Ctrl+S to save files would also be nice. Also, a list of most recent files, displayed under the file menu, would facilitate Digital Ear sessions. However, the ability to manipulate the MIDI event "cursor" (the red vertical line in the VFD) using the arrow keys is a welcome included feature.

The ToolTip help – the yellow rectangles that pop up when you station the pointer over a control – is outstanding. For example, the ToolTip for the Specify Note Range control reads: "Define the note range of your instrument or voice. It is very important to narrow this range as much as possible." What's the last app you used that had a ToolTip as clear, thorough and helpful as that?

The Basic Tools

Let's walk through a session to convert a Wave file to MIDI, and examine the tools Digital Ear supplies to help achieve this.

You'll first create a Wave file with a single melody line. Digital Ear won't process harmonies. Digital Ear requires that the Wave be in 44.100 kHz, at 16-bits of resolution. Once you have such a file, you can open it in Digital Ear, and press the Start button. You'll then get a prompt for the file name to save the MIDI to. Digital Ear begins processing the file, while displaying the MIDI notes on the keyboard graphic. That's all that's necessary to generate a MIDI file.

With other apps, there's a more complicated process involving selecting a tone file appropriate for the Wave, and perhaps doing some other manipulations. At best, these other programs make Wave-to-MIDI conversions a hassle, especially for those who don't know much about signal processing. Thus, Digital Ear earns high marks for this simplicity factor.

Fine Tuning

We've outlined the basic Wave-to-MIDI process, including Digital Ear's controls needed to do it. But Digital Ear offers many controls to help you optimize the resultant MIDI file.

In the Settings dialog box, Digital Ear has a control called Harmonic Threshold. With this control, you can essentially filter out the non-harmonic sounds produced by the instrument on the Wave file. An example of a non-harmonic sound would be the pick noise for guitars, or the overtones that the human voice naturally produces.

Initial attempts at using this control were disappointing; attempting to filter out the non-harmonic sounds from a Wave file featuring a simple arpeggiation by a human voice resulted in a MIDI file with some of the sung notes, and many "garbage" tones. Based on the success in converting the sample saxophone-sound Wave file supplied with Digital Ear, this seems like a temporary setback.

Regarding the controls in general, the help manual offers this encouraging tidbit: "[Digital Ear needs to be customized] only once for each type of instrument." So, once the problem in converting the voice arpeggio is fixed, one should be able to apply its customization settings to other voice files.

The trouble is, the help manual doesn't offer any hints about specifically how to customize Digital Ear to a particular instrument. For example, what settings for harmonic resolution and for time resolution should be used to get the best MIDI file from the problematic arpeggio Wave? This particular issue would probably impact beginners more than experienced digital audio folk.

Experimenting with the Specify Instrument's Note Range control offered by the Settings dialog box produced better results for the Wave arpeggiation. When the note range was knocked down from its default to a range more suitable for a baritone voice, the new MIDI conversion showed significant improvement. The piano icon used in this control to allow the user to set the note range could make the conversion process easier if it sounded a tone when you clicked a key, but such a feature will have to wait for a new version of Digital Ear. However, actually selecting the range is made fairly easy: Click a piano key to identify one end of the range, and shift-click to pick out the other end.

Digital Ear lets you control how and what MIDI messages get created and sent to the MIDI out, including selecting the MIDI out device. For instance, It's pretty easy to select the GM instrument that you want to convert your Wave to using the provided combo box. Select the MIDI channel for your output in the same control grouping. Send brightness events to the MIDI controller of your choosing, and boost the brightness with the Gain slider. You can also sync up the output MIDI file with the Beats Per Minute control and the Send Tempo Information control.

In addition to these controls, which work on the MIDI messages after the Digital Ear Engine creates them, there's another control that affects the engine itself: the Time Resolution slider, and the neighboring Overlapping Frames check box. These controls determine the time rate at which Digital Ear grabs data from the Wave file. Beginning users may be interested in reading, from the Digital Ear help file and ToolTips, that lower resolution, i.e. having the engine grab less often from the Wave file, makes for more accurate pitches in the output MIDI file. (This is definitely a case where "less is more.") Selecting the Overlapping Frames check box lets you, according to the Help, get the "best of both worlds"; it lets you double resolution without the errors. If you remember nothing else about this resolution stuff, do remember this: lower pitches are converted more accurately with lower resolution.

Digital Ear does let you save the settings you've made for a particular Wave-to-MIDI session. There is some initial confusion as to how users apply this: after you've created a MIDI file, and made some adjustments to the default settings, you should be prompted to save these settings before quitting the session. Digital Ear does not prompt you. You have to explicitly elect to save the settings from the Settings menu.

Getting in Tune

Two buttons in the main window give you enhanced control over the accuracy of Wave-to-MIDI sessions. These are Pitch Quantize and In-Tune Wizard. Quantizing pitches will "pull" notes that are slightly off key to the nearest semi-tone. This is needed for instruments that you can't (easily) tune to exact MIDI specs, such as pianos. Use In-Tune Wizard to have Digital Ear analyze an entire sample and get it in key. This would benefit instruments that aren't tuned around a reference tone, such as the human voice. There's a third button in the main window: Auto Correct, which fixes errors in the Wave-to-MIDI process. The corrections are based on estimations rather than only the actual measured pitch data in the Wave file.

More Control

In addition to the Octave, Fine Tuning, Volume, and Brightness controls described earlier, the main window has some additional controls to improve the Wave-to-MIDI conversion. The Sensitivity slider causes Digital Ear to be more receptive to Wave data to create MIDI Note On events. What's cool about this is the ability to move the slider as the MIDI file is playing; if you change the sensitivity during play, the MIDI player rewinds and plays again automatically to reflect the new sensitivity setting. However, having this loop feature available only when making a change during a single playback is a bit frustrating; users will want to be able to loop the MIDI playback on demand. The ability to loop MIDI playback continuously while making parameter adjustments would be a nice improvement.

Conclusion

Digital Ear has a high caliber interface that is very easy to begin using. The controls are centrally located, so you're not rummaging through reams of dialog boxes to change settings. Some additional support is needed to enable faster sessions, including keyboard shortcuts and hints on specifically how to tune the settings for maximum performance.

Once the parameters for a particular Wave file are set correctly, it does a decent job of converting Wave files to MIDI files. However, figuring out how to set these parameters can be time-consuming for the beginner. The aforementioned example with the Wave file containing the human voice arpeggio sounded good once the note range was set properly. But the settings for this file didn't help when trying to convert a second Wave file: that of a short riff on acoustic guitar. Here, despite messing with the note range and some other parameters for several minutes, the output was still muddy. Those with sufficient persistence or knowledge of digital audio should have greater success in minimizing the time needed to tune Digital Ear's engine correctly.

Pros

• Easy to begin using.
• Very stable. No unexpected behavior or crashes.
• Helpful documentation and ToolTips.
• Responsive customer support.

Cons

• No explanation on how to adjust settings for various instruments.
• No undo.
• Lacks useful keyboard shortcuts and a recent file list.
• Doesn't prompt to save changed settings.