After nearly four years, Bose is finally updating its famous active noise-canceling headphones as the Bose QuietComfort 45. The updated headphones feature improved noise cancellation, a new Aware mode that captures ambient noise, improved voice separation, and an impressive 24-hour battery life.

Bose touts in the press release that the upcoming headphones have great audio performance, all-day comfort and stability, simple operation, strong connectivity, and an updated design. Here's everything we know so far about the Bose QuietComfort 45, from pricing and release date to new features and design.

The Bose QuietComfort 45 is available for pre-order now, with a release date of September 23; the Bose QuietComfort 45 will cost $329.95.

Price-wise, the QuietComfort 45 is about $20 less than the four-year-old Bose QuietComfort 35 II headphones.

Interestingly, the QuietComfort 45's lower price is $20 below the MSRP of the excellent Sony WH-1000XM4 headphones. We compared the two headphones directly in our Bose QuietComfort 45 vs. Sony WH-1000XM4 showdown.

The Bose QuietComfort 45 is designed for ease of use; it offers two modes, Quiet and Aware; Quiet, as the name implies, is Bose's new active noise cancellation system and new electronics package. ANC is intended to tune out more mid-range frequencies, such as those found on trains, in offices, and in cafes.

Aware mode gives users "total transparency" so that sounds from the outside world can be heard "naturally, clearly, and quickly"; we'll have to try it out in person when we present our review in September.

Bose also touts its Voice Isolation feature, which isolates voices during a call and tunes out things like coffee grinders and dog barking.

Battery life for the Bose QuietComfort 45 is claimed to be 24 hours; Bose does not clarify whether that is with ANC turned on. We assume it is without ANC. It can also handle 20 hours of "continuous conference calls."

Like most recent headphones, the Bose QuietComfort 45 supports USB-C charging. A full charge takes two hours, but a 15-minute quick charge provides three hours of playback. Again, this is with ANC turned off.

The Bose QuietComfort 45 features both Bluetooth 5.1 for connecting to multiple devices and Bose SimpleSync for pairing with Bose Soundbars.

In terms of design, the Bose QuietComfort 45 returns to a more traditional look. Unlike the Bose 700's, where the headband is molded into the sides of the earcups, the QuietComfort 45 is kind of boring in comparison. However, Bose would argue that the design is "iconic."

In Bose's QuietComfort 45, "pleats and puckers have been removed from the soft material and the gaps between components have been replaced with smooth transitions that are durable, lightweight, and flat for storage in the included compact carrying case It folds flat for storage in the included compact carrying case.

At first glance, the headphones may not look much different from the QuietComfort 35, but Bose has made some subtle tweaks that should amount to a substantial change in feel.

As for colors, Bose offers triple black and white-smoke options. Both have a matte finish.

Bose pushes simplicity hard, perhaps as a jab at the Sony WH-1000XM4's more cumbersome touch controls. The right cup has four buttons for volume, power, and Bluetooth paring. The left cup has buttons for switching between different modes and muting the microphone.

The $329 Bose QuietComfort 45 is more affordable than the $379 Bose 700, but there are some additional differences, which we covered in full in our Bose QuietComfort 45 vs. Bose 700 showdown, but the main differences are.

The Bose 700 has a sleek design with touch controls, while the QC45 relies on buttons. However, the QC45's battery life is 24 hours, longer than the Bose 700's 20 hours.

The QC45 only offers quiet and recognition modes, while the Bose 700 offers 11 levels of adjustable noise cancellation. Also, only the Bose 700 has Alexa and Google Assistant built in, while the QC45 only offers native voice assistance.

Other benefits unique to the Bose 700 include adjustable EQ and Spotify Tap playback.

The Bose QuietComfort 45 appears to have what it takes to make our Best Noise-Canceling Headphones list, but we need to put it to the test before we give our verdict. For now, we are pleased to see that Bose has improved comfort while providing 24-hour battery life.

We're also eager to see how well the noise cancellation works and to try out the Aware mode for ambient listening; stay tuned for our review of the Bose QuietComfort 45, which we'll be reviewing in the coming weeks.