This has become a growing problem:
- As land lines have been reclaimed or replaced in the phone company networks;
- As the growing older population has lost hearing sensitivity.
- Because secondary carriers don't always receive the best or least crowded connectons (especially in case of residential versus business which pay more for service).
If you are getting static and cross talk (hearing radio or other people's converstations) notify the phone company and you will probably provided a new connection.
IF the problem is persistent without such interference, consider an amplified phone--some states (California for instance under Federal auspices) makes such equipment available free to hearing impaired. Also check the quality of your household wiring and connections.
Check with you neighbors--if they don't have the same problems, complain to the phone company. If they do, complain together.
Finally, some phones are simply too poor in quality to provide good sound. You might want to upgrade: either the phone set or its line or handset cord.