“What did he just say?”

Those are some of the most commonly uttered words in my home. No matter how much my wife and I crank up the TV volume, the actors in streaming movies and shows are becoming increasingly difficult to understand. We usually end up turning on the subtitles, even though we aren’t hard of hearing.

We’re not alone. In the streaming era, as video consumption shifts from movie theaters toward content shrunk down for televisions, tablets and smartphones, making dialogue crisp and clear has become the entertainment world’s toughest technology challenge. About 50 percent of Americans — and the majority of young people — watch videos with subtitles on most of the time, according to surveys, in large part because they are struggling to decipher what actors are saying.

“It’s getting worse,” said Si Lewis, who has run Hidden Connections, a home theater installation company in Alameda, Calif., for nearly 40 years. “All of my customers have issues with hearing the dialogue, and many of them use closed captions.”

The garbled prattle in TV shows and movies is now a widely discussed problem that tech and media companies are just beginning to unravel with solutions such as speech-boosting software algorithms, which I tested. (More on this later.)

The issue is complex because of myriad factors at play. In big movie productions, professional sound mixers calibrate audio levels for traditional theaters with robust speaker systems capable of delivering a wide range of sound, from spoken words to loud gunshots. But when you stream that content through an app on a TV, smartphone or tablet, the audio has been “down mixed,” or compressed, to carry the sounds through tiny, relatively weak speakers, said Marina Killion, an audio engineer at the media production company Optimus.

It doesn’t help that TVs keep getting thinner and more minimal in design. To emphasize the picture, many modern flat-screen TVs hide their speakers, blasting sound away from the viewer’s ears, Mr. Lewis said.

There are also issues specific to streaming. Unlike broadcast TV programs, which must adhere to regulations that forbid them from exceeding specific loudness levels, there are no such rules for streaming apps, Ms. Killion said. That means sound may be wildly inconsistent from app to app and program to program — so if you watch a show on Amazon Prime Video and then switch to a movie on Netflix, you probably have to repeatedly adjust your volume settings to hear what people are saying.

“Online is kind of the wild, wild west,” Ms. Killion said.

Subtitles are far from an ideal solution to all of this, so here are some remedies — including add-ons for your home entertainment setup and speech enhancers — to try.

Decades ago, TV dialogue could be heard loud and clear. It was obvious where the speakers lived on a television — behind a plastic grill embedded into the front of the set, where they could blast sound directly toward you. Nowadays, even on the most expensive TVs, the speakers are tiny and crammed into the back or the bottom of the display.

“A TV is meant to be a TV, but it’s never going to present the sound,” said Paul Peace, a director of audio platform engineering at Sonos, the speaker technology company based in Santa Barbara, Calif. “They’re too thin, they’re downward and their exits aren’t directed at the audience.”

Any owner of a modern television will benefit from plugging in a separate speaker such as a soundbar, a wide, stick-shaped speaker. I’ve tested many soundbars over the last decade, and they have greatly improved. With pricing of $80 to $900, they can be more budget friendly than a multispeaker surround-sound system, and they are simpler to set up.

Last week, I tried the Sonos Arc, which I set up in minutes by plugging it into a power outlet, connecting it to my TV with an HDMI cable and using the Sonos app to calibrate the sound for my living room space. It delivered significantly richer sound quality, with deep bass and crisp dialogue, than my TV’s built-in speakers.

At $900, the Sonos Arc is pricey. But it’s one of the few soundbars on the market with a speech enhancer, a button that can be pressed in the Sonos app to make spoken words easier to hear. It made a big difference in helping me understand the mumbly villain of the most recent James Bond movie, “No Time to Die.”

But the Sonos soundbar’s speech enhancer ran into its limits with the jarring colloquialisms of the Netflix show “The Witcher.” It couldn’t make more fathomable lines like “We’re seeking a girl and a witcher — her with ashen hair and patrician countenance, him a mannerless, blanched brute.”

Then again, I’m not sure any speaker could help with that. I left the subtitles on for that one.

Not everyone wants to spend more money to fix sound on a TV that already costs hundreds of dollars. Fortunately, some tech companies are starting to build their own dialogue enhancers into their streaming apps.

In April, Amazon began rolling out an accessibility feature, called dialogue boost, for a small number of shows and movies in its Prime Video streaming app. To use it, you open the language options and choose “English Dialogue Boost: High.” I tested the tool in “Tom Clancy’s Jack Ryan,” the spy thriller with a cast of especially unintelligible, deep-voiced men.

With the dialogue boost turned on (and the Sonos soundbar turned off), I picked scenes that were hard to hear and jotted down what I thought the actors had said. Then I rewatched each scene with subtitles on to check my answers.

In the opening of the show, I thought an actor said: “That’s right, you stuck the ring on her — I thought you two were trying to work it out.”

The actor actually said, “Oh, sorry, you still had the ring on — I thought the two of you were trying to work it out.”

Whoops.

I had better luck with another scene involving a phone conversation between Jack Ryan and his former boss making plans to get together. After reviewing my results, I was delighted to realize that I had understood all the words correctly.

But minutes later, Jack Ryan’s boss, James Greer, murmured a line that I could not even guess: “Yeah, they were using that in Karachi before I left.” Even dialogue enhancers can’t fix an actor’s lack of enunciation.

The Sonos Arc soundbar was helpful for hearing dialogue without the speech enhancer turned on most of the time for movies and shows. The speech enhancer made words easier to hear in some situations, like scenes with very soft-spoken actors, which could be useful for those who are hearing-impaired. For everyone else, the good news is that installing even a cheaper speaker that lacks a dialogue mode can go a long way.

Amazon’s dialogue booster was no magic bullet, but it’s better than nothing and a good start. I’d love to see more features like this from other streaming apps. A Netflix spokeswoman said the company had no plans to release a similar tool.

My last piece of advice is counterintuitive: Don’t do anything with the sound settings on your TV. Mr. Lewis said that modern TVs have software that automatically calibrate the sound levels for you — and if you mess around with the settings for one show, the audio may be out of whack for the next one.

And if all else fails, of course, there are subtitles. Those are foolproof.