"Voice Recording on a Computer"

Trio Systems has given The Sonic Spot permission to provide all of the included text in the Electronic Music and Audio Guide. The text has been adapted from the SoniClear documentation to help with a broader range of software packages. To take advantage of the topics discussed in this article, you can download Trio Systems SoniClear demonstration software.

1. Audio Hardware Options

Sound is a very delicate thing. Each step of the process of making a sound recording can introduce noise and distortion that reduces its appeal or usefulness. Having the best hardware can make a dramatic difference in the resulting recording.

The first link in the recording "chain" is the microphone. Every type of microphone is different and will interact with the voice characteristics of the person using it. The microphones supplied with sound cards are generally of very poor quality. There are a limited number of options for recording to the microphone input of sound cards. This requires a microphone that was specifically designed for sound card use.

Most high quality microphones, cannot be connected directly to the sound card. They must be connected first to a separate microphone preamplifier ("preamp"). The preamp is then connected to the Line Input of your sound card. With this setup the recording sound quality will be improved in a number of ways. The microphone options are greatly expanded, allowing you to pick a microphone that is best for the application and your budget. Most microphone preamplifiers built into sound cards are of poor quality. As a result, recording the sound through the Line input, instead of the Mic input, will also improve the results.

Using a microphone stand is a good idea. This will eliminate the problem of microphone handling noise being added to the recording. It will also make it possible to position the microphone in the best location for the person speaking.

Sound cards vary widely on their sound quality. The largest problem is with the noise level of the cards. Although most sound cards report a respectable "signal to noise ratio" (the measure of noise added by the card), in reality, the noise level is higher than the specifications. This causes the recording to have more background noise, especially when recording using the built-in microphone input. Generally, all currently available consumer-grade sound cards (under about $150) will be of similar quality. The main differences of cards in the group are in their ability to play MIDI instruments, which does not affect recording quality. Sound cards designed for professional use will be of higher quality and considerably more expensive. If you are considering using a high-end sound card, make sure that it is MPC compatible ("multimedia PC", the basic Windows sound card standard). If the sound card has only DirectX compatibility, it may not work with your recording software.

2. Using The Windows Volume Control Program

There may be times you will need to use the Volume Control program built-in to Microsoft Windows. This is the program that controls all the features of the sound card. For example, there may be sound sources other than Microphone and Line that you want to record. Also, some sound cards may be incompatible with your recording software's sound card controls. In these cases, you will need to use the Volume Control program along with the software.

The Volume Control program can be started by double clicking the speaker icon in the "system tray" (the icons at the lower right corner of the screen). If there is no speaker icon displayed, consult with your computer documentation for instructions on controlling the sound card.

When the Volume Control program starts running, it displays the default playback volume controls. This display can be modified by selection from the menu bar Options/Properties. You have the following controls:

  • Mixer device - Your computer can have more than one sound card. Most recording software only works with the first card installed in the system (this should be the first card displayed in this selection box). You should not normally need to change this setting.
  • Adjust volume for - You select Playback (the default), Recording, or Other. To control the playback volume, make sure Playback is selected. To set recording sources and levels, select Recording.
  • Show the following volume controls - You can display all of the controls at once, or select just the controls you are interested in using.

You will need to start your recording software and the Volume Control programs together. Often, the changes made in the Recording controls for Microphone and Line sources will also be displayed on the corresponding controls of the recording software. And changes made in the recording software will display in the Volume Control program as well.

Some sound cards are supplied with a custom Volume Control program that displays the controls differently from the standard Windows Volume Control. Consult your sound card documentation for help.

3. Getting the Best Quality Sound

In addition to having the best audio hardware that fits your budget, you will need to learn a few recording techniques to get the best possible sound quality. This involves experimentation with a few recording parameters to find what works best in your situation.

Optimally, the recording of voice should be made in a quiet room. Unfortunately, most computers are very loud, so you may need to compensate for this in several ways.

Pick the Right Microphone

The microphone you use should be "unidirectional" (picks up sound in a single direction). "Omnidirectional" microphones pick up sounds from all directions, resulting in all noise in the room being recorded along with the voice. Use the best microphone that meets your budget requirements. The microphone will be the single largest determinant of sound quality for your recordings.

Position the Microphone

Position the microphone close to the person speaking. For starters, try 6 inches in front of the mouth. The exact distance will depend on how loudly the person speaks, the type of microphone, and the desired type of sound. Also experiment with having the microphone in different positions relative to the mouth. For example, directly in front of the mouth, below the mouth pointing up, above the mouth and nose, pointing down, to one side or other of the mouth. You want the microphone to pick up a pleasing vocal sound with as little room noise as possible.

Most microphones will increase the level of bass frequencies when they are placed closer to the mouth. Close positioning will also increase the amount of detailed vocal sounds that are recorded. This can be a problem for such sounds as wind noises from the popping of "p" sounds and the sibilance of "s" sounds. Changing to a better microphone, or moving the microphone to a different location can help control these problems.

Set the Recording Level

Most people who have recorded with analog tape recorders have learned that recording to the highest level will provide the best results. With digital recording in general, this is not true. You want to make sure that the sound level is in a medium range on the level meters for most of the recording. If the clipping indicators turn on, it may indicate that an overload of the digital signal has occurred. This can cause a buzzing-like distortion to be added to the recording. Although the recording software may have a feature to remove some of this distortion, you will have better results when clipping does not occur.

Practice the loudest sections of the material to be recorded while the recording software's level monitoring is enabled. This will allow you to see the volume level display and clipping indicators before making the actual recording. Remember to speak with the same intensity during the level setting process as you will use in the actual recording.

Speak with a Smooth and Consistent Loudness

Your presentation will be much easier for the listener to hear if all the words are spoken in a strong, consistent fashion, especially when converting the recorded output to an Internet audio format. The dynamic range of Internet audio and other highly compressed files is very limited. Words that are suddenly very soft in a sentence may be lost in the translation to these file formats. Practice recording the text and listening to the results after conversion to a compressed audio format to refine the presentation.

Copyright © 1999 Trio Systems LLC