Americans have long expressed dissatisfaction with their cable and Internet service. This year, they seem to have grown even more dissatisfied.

The American Customer Satisfaction Index released on Tuesday the results of its latest study on customer satisfaction with cable TV, Internet and phone service providers, saying that the results declined to a seven-year low. Of the 43 industries on which the survey solicits opinions, TV and Internet companies tied for last place in customer satisfaction.

Cable TV and Internet providers have faced particular scrutiny in a year filled with talk of mergers in the industry. Regulators’ reservations about Comcast $45 billion bid for Time Warner Cable killed the deal. Charter Communications announced deals last week to buy Time Warner Cable and Bright House Networks for a total of $67.1 billion.

“Internet and TV have always been among the lowest scoring,” said David VanAmburg, director of the Index. “But this year they’re at the very bottom.”

The study, which is based on more than 14,000 consumer surveys, gives companies a rating from 0 to 100. For cable TV service, Comcast’s rating dropped by 10 percent over last year, for a score of 54, the Index found. Time Warner dropped by 9 points, to a 51, tying Mediacom Communications for the lowest score among the more than 300 companies evaluated by the Index.

For Internet service, Time Warner received a more favorable rating than last year, earning a score of 58, compared with 56 for Comcast, 57 for Charter, 68 for Verizon FiOS and 69 for AT&T U-verse.

“Customer service in these industries has long been bad,” Mr. VanAmburg said of Internet and TV providers. “They don’t have a good business model for handling inquiries with efficiency and respect. It goes back a decade plus.”

Even though those complaints are longstanding, customer frustration has risen along with the ever-rising prices. “You compound all that with the prices customers are paying, and that’s the final straw,” he said. “They’re opening bills each month and saying ‘I’m paying how much?'”

But in an age of over-the-top viewing options like Hulu and Netflix, customer dissatisfaction may increasingly translate to companies’ bottom lines.

“There was a time when pay TV could get away with discontented users without being penalized by revenue losses from defecting customers,” said Claes Fornell, chairman and founder of the Index. “But those days are over.”