You're using your voice properly if it is clear and efficient, and if you have no fatigue, hoarseness, pain or other negative symptoms.

You could be misusing your voice if people appear to be paying more attention to the pitch, loudness or quality of your voice than to what you're saying. You're probably abusing your voice if you suffer discomfort or pain when talking or singing.

Voice abuse can lead to such disorders as laryngitis, vocal nodules, nodes, polyps or contact ulcers.

Taking care of your voice should include adequate hydration. "It's important," stresses voice coach Rafi Dworsky, "to drink about two quarts of water a day. You breathe out two quarts a day just during your normal exhalation. (An opera singer can lose as much as six to eight quarts of water during a three- or four-hour opera.)

Another mistake: going to bed or napping after eating a big meal. If you lie flat on your back or stomach after eating a big meal, "the stomach acidity in many people can seep up the esophagus and burn the vocal chords," says Dworsky. You wake up the next morning or after your nap and "your voice is just ruined." It can take several hours to get it back.

Anyone with questions concerning speech or voice problems may contact Helpline, a collect-call telephone service operated by the American Speech-Language-Hearing Association, weekdays, 8:30 a.m.-4:30 p.m., 0-301-897-8682, or write National Association for Hearing and Speech Action, 10801 Rockville Pike, Rockville, Md. 20852.

Speech-language pathologists in this area charge about $30-$50 for an hour-long session. Treatment could range from only one or two sessions to a year or more.

Among other area resources for voice/speech diagnosis and therapy:

* George Washington University Speech & Hearing Center, (202) 676-7360. Initial fee of $42 for evaluation; therapy sessions, $16 an hour.

* Howard University Speech & Hearing Clinic, (202) 636-6990. Contact Darlene Gripper. No charge for evaluation or therapy.

* University of the District of Columbia Speech & Hearing Clinic, (202) 727-2608. No charge for evaluation or therapy.

* University of Maryland Speech Clinic, (301) 454-2546. Contact Susan Patrick. Initial evaluation, including hearing screening, $50; therapy sessions, by the semester, ranging from $91 a semester for group therapy, to $312 a semester (three times a week). Can be prorated on an hourly basis.

* Numerous area hospitals also offer diagnoses and therapy.

For information on voice dynamics seminars and workshops, write Virginia Jacobs: P.O. Box 30795, Bethesda, Md. 20814-0780.