Fred Baird grew up on a ranch in south Texas where everyone, including his mother, commonly used high-powered rifles.

By the time he was 14, Baird, a professor who teaches business courses at Austin Community College, was already having self-inflicted hearing problems. Almost 50 years later, about 90 percent of Baird’s hearing is gone.

Hearing aids have been a part of Baird’s life for a long time, and he’s gone through many sets of them over the years. But like a lot of other people — seniors, frequent live-music enthusiasts and military veterans especially — Baird is finding that within the last five years, hearing aids have improved dramatically.

He’s currently using the Beltone First, one of several hearing aid models made to work with Apple’s iPhone. Some new hearing aids includes built-in Bluetooth so that users can change settings (volume, bass, treble and lots of other adjustments) wirelessly from their phone. The devices can also pipe in phone calls, music from services such as Pandora and audio from FaceTime video calls right to Baird’s ears. They can even connect to tablets or to a car stereo system for music listening and hands-free calls while driving.

“My hearing loss is pretty profound,” Baird said. “If you can’t hear, people treat you like you have diminished capacity. This basically makes my life normal.”

App-enabled hearing aids have become common over the last five years as smartphones have come to dominate the wireless market. But hearing aids were already going through several evolutionary changes long before that, said Soriya Estes, president and founder of Estes Audiology Hearing Centers.

Since the mid-’90s, hearing aids have evolved from volume amplifiers to sophisticated signal-processing devices that do a lot more than make sounds louder.

“For two decades they’ve been advancing,” Estes said. “The processor in there is quicker than my computer workstation as far as analyzing sound.”

Hearing aids must analyze sound around a user, filter out unwanted noise, adjust for bass and treble and focus on the right input before outputting sound back out. “They have to do all these functions, adapting in lots of different environments, and they have to do that automatically,” Estes said.

The other big evolution in hearing aids — whether they’re worn inside or over the ear — is wireless connectivity. Bluetooth devices have gotten smaller and the technology now fits in the hearing aid itself instead of in an external streaming box that would in turn connect to someone’s phone.

“It’s something that in the last five years has turned them into more of a personal communication device versus just hearing aids,” said Estes. At her offices, Estes has high praise for Starkey Halo devices, which run from about $3,000 to $6,000, a not uncommon price range for hearing aids.

Like the Beltone First, the Halo hearing aids allow a hearing-aid wearer to adjust their own settings with a mobile app on their phone. But smartphone technology offers a few other useful bonuses. If Baird likes the settings he’s created for a specific coffee shop, for instance, he can save those adjustments as a preset on his phone. Every time he visits the same coffee shop, the software is smart enough to “geolocate” that and switch to those settings automatically.

Because they’re paired with a phone, hearing aids can also be located geographically if they’re lost. If the batteries on the hearing aid have expired, the apps can at least let a user know where the hearing aids were last detected.

The boomer generation is largely driving the technology on hearing devices, Estes said. “Boomers are demanding this. They’re still in the work force, they’ve very tech-savvy, and they have hearing loss.” She said that insurance policies increasingly are covering hearing devices.

According to data compiled by the National Institute on Deafness and Other Communication Disorders, about 30 million people in the United States ages 12 or older, about 1 in 8, have hearing loss in both ears. About 15 percent of Americans ages 20 to 69 have high-frequency hearing loss due to noise exposure at work or during leisure time. In 2014, sales of hearing aids grew to more than 3 million in the U.S., according to the Hearing Association of America.

Andrew Cearnel, clinic director at Beltone Audiology, said the technology “has really stepped up” in the last few years to keep up with the increasingly tech-focused lives of patients. The Beltone devices, which use an app called “HearPlus,” will be compatible with Android devices later this year, he said.

Cearnel said that not every patient needs the higher-end hearing aids. Some who spend most of their time at home may not need the fastest processors, which are a must for executives who spend time in meetings and in noisy spaces such as conferences or bars.

But hearing aids that can be controlled by app and stream audio wirelessly are becoming common enough that they’re becoming available even in more entry-level devices, he said.

The devices aren’t perfect. Battery life is still an issue; Baird uses his hearing aids constantly and has to change out the batteries (which are inexpensive) every few days.

Estes said that even for hearings aids that don’t offer Bluetooth connectivity, such as a line of disposable in-ear ones called Lyric that are practically invisible, they have to be swapped out every few months when the batteries run out.

And Baird, who owns an iPhone 4S, sometimes runs into app problems that have less to do with the Beltone First than with glitches and performance issues on the phone itself.

Some patients aren’t interested in connecting a hearing aid to a smartphone (or interested in using a smartphone to begin with), while some older users with severe arthritis don’t have the hand coordination to use them. For them, an implanted hearing aid without Bluetooth might be a better option.

But a larger problem is that many people who need hearing aids don’t know it yet. Estes said that, on average, it takes five to seven years for someone with hearing loss to seek treatment. About 90 percent of hearing loss is gradual in nature, and many don’t notice it’s happening.

“That’s seven years of saying, ‘Huh? Huh?’ and turning up the TV or talking loudly at restaurants year after year,” Estes said.

Baird said that of all the hearing aids he’s used over the years, the Beltone First is “undoubtedly the best” and has given much more freedom in his daily life. In demonstrating the gear, he switches to a Miles Davis song on his iPhone and listens contentedly.

“You have to have used these for a while to really appreciate this,” he said.