A new pair of Sony wireless headphones has been spotted in an FCC filing that may reveal the first specs and charging case design for Sony's WF-1000XM4

The filing, discovered by the Walkman Blog, does not name the WF-1000XM4, which is expected to be Sony's answer to the Apple AirPods 3 and AirPods Pro 2 However, given that it has already been leaked and is the only one of Sony's unreleased headphones to leak, it seems like a pretty safe bet that the filing actually covers the WF-1000XM4 And it suggests that a true wireless bad is nearing completion

The design image of the charging case is simply drawn, and although only a top-down view is shown, it is consistent with the elongated cases of previous Sony earphones like the original WF-1000XM3 and WF-SP800N The WF-1000XM3 is feature active noise cancellation (ANC), and the WF-1000XM4 is almost guaranteed to retain this key feature

For the new upgrade, the earphones in this document use Bluetooth 52 Therefore, the WF-1000XM4 will gain many wireless performance advantages over the WF-1000XM3 as well as the current AirPods Pro model, which uses Bluetooth 50 For example, the WF-1000XM4 can play music with lower bandwidth and power consumption by using Bluetooth 52's low-energy (LE) audio capabilities

Bluetooth 52 also introduces the Isochronous Channels feature, which makes it easier for a single pair of headphones to connect to multiple source devices simultaneously and switch seamlessly between them

The WF-1000XM4 also appears to feature an upgraded MediaTek SoC, the MT2822S Details of this chip have not yet been disclosed, but the Walkman Blog claims that it is a rebranded Airoha AB1568 If so, the WF-1000XM4 will support the same 192kHz/24-bit lossless audio as the WF-1000XM3, while also offering much improved power management

The filing even includes hints about a potential release date, as the FCC's short-term non-disclosure agreement expires on September 27 of this year Whatever these new headphones are, Sony will want to officially announce them before then, so it is quite possible that the WF-1000XM4 will be released before winter 2021

That would put it in competition with the AirPods 3 and Google Pixel Buds A, which are rumored to be released in late 2021