My friend & neighbors all have the same phone problem?

All the people in a certain area whether they have a cell phone or land line, all hear a slight to moderate ECHO when they talk on the phone at their residence. The echo comes and goes during a conversation sometimes loud. The phone company has been called,said there may be a problem, AFTER a short 5 min, test, but demand a $55 charge just to come out. Then there are all sorts of charges just to find out. Why both cell AND land lines with this same problem. Example one uses the only offered land line and another uses Cricket or Verison? Help Mr. Wizard. There IS a local business airport less than a mile from this area. The questioner has lived in the area for over 20 years and this, is in the past several weeks only. Any thoughts?.....Thanks