The Emu Capture Tool is a graphical front end for recording audio directly into your computer with the option of generating an Emu template file to match the data. The tool can be used to prompt a speaker with either words or phrases and allows recordings to be previewed and re-recorded easily.
The tool begins with a Wizard dialogue which gathers various parameters for the recording session. These are as follows:
Database Name: this is a name for the database and will be used as the name of the template file (if any) written by the capture tool.
Speaker/Set Identifier: this is a prefix to be used to name the files written during recording, eg. if the speaker identifier is bob then files bob1.wav, bob2.wav etc. will be written.
Prompt File: the name of a file containing prompts for the recording session. This file should be a simple text file (eg. created with notepad rather than Word) containing one prompt per line. Prompts can be single words or phrases, long phrases will be wrapped onto multiple lines if they are too long to fit on the screen. A sample word list file is provided in the file lib/capture/examples/wordlist.txt in your Emu installation. Prompt files may contain international characters if they are encoded in the UTF-8 character encoding.
Output Directory: choose a directory to write the recorded files to. The directory will be created if it doesn't already exist.
In the second window you will see:
Recording Device: choose the input device to be used for recording. The list is generated from the valid recording devices on your computer.
Sample Rate: choose the sample rate for the recordings, the list is generated from the valid sample rates for the recording device you have chosen. To make high quality recordings you should choose a sample rate of at least 16000 samples per second.
Playback Device: choose the device to use for playback of recordings during the recording session.
In the third window you will see:
Template File: check this box if you wish the to have an Emu template file generated automatically.
Template Skeleton: the name of a skeleton file from which the template will be generated. A template skeleton is just like a regular Emu template file but with some of the path information replaced by markers. In this file, which usually has a .tpx extension, the location of the signal files is marked with %signals. These will be replaced with the real values when the template is saved. All other parts of the template skeleton are left unchanged. An few example files are included in the lib/capture/examples directory in your Emu installation but you are free to create your own.
After this dialogue you will be prompted to confirm the various parameters and after doing so will see the main recording window (Figure 3.7, “The Emu Recording Tool”). This consists of a large central area for text, a waveform display at the top and a control area at the bottom. To begin recording click the mouse on the main part of the display and the first prompt will be displayed. Once a prompt is displayed clicking and holding the left mouse button on the prompt window starts recording and releasing the mouse button stops. The window turns red while recording and the waveform is shown at the top of the screen.
You can move forward or backward in the prompt list, play the current recording or restart your session using the buttons at the bottom of the window. As you record a word it is saved; if you record again with the same prompt visible, the first recording is overwritten.
Once the recording session is complete you can process the files further using one of the Emu signal processing tools. The Pitch and Formant tool can be used to generate pitch and formant tracks for each file; the Keil Tkassp tool can be used to derive these (using different algorithms) and other tracks.