Acquired identifiable intangible assets, and related accumulated amortization, as of June 30, 2023 and December 31, 2022 consisted of:


	June 30, 2023
	Gross Carrying Value			Accumulated Amortization			Net Book Value
	(in thousands)
Customer relationships	$	8,085		$	6,986		$	1,099
Tradenames		3,066			2,378			688
Developed technology		1,884			1,557			327
Foreign currency		(1,225	)		(1,349	)		124
Total Intangible Assets	$	11,810		$	9,572		$	2,238


	December 31, 2022
	Gross Carrying Value			Accumulated Amortization			Net Book Value
	(in thousands)
Customer relationships	$	8,085		$	6,750		$	1,335
Tradenames		3,066			2,147			919
Developed technology		1,884			1,495			389
Foreign currency		(1,375	)		(1,344	)		(31	)
Total Intangible Assets	$	11,660		$	9,048		$	2,612

In connection with the October 2012 acquisition of TB Europe, the acquired intangible assets related to customer relationships is being amortized over an estimated useful life of thirteen years with the amortization being included within sales and marketing expense.

In May 2019, the Company completed its acquisition of the business and assets of ROCCAT. The acquired intangible assets relating to developed technology, customer relationships, and trade name are subject to amortization. During the fourth quarter of 2022, the Company made the decision to increasingly leverage the Turtle Beach brand across our product portfolio including PC products over time. Due to this decision, the Company prepared an impairment calculation to determine the present value of the ROCCAT tradename asset using the relief from royalty method. As a result of the present value calculation, in the fourth quarter 2022, the Company recorded an impairment charge of $0.8 million for the ROCCAT tradename intangible asset.

In January 2021, the Company completed its acquisition of the business and assets relating to the Neat Microphones business. During the fourth quarter of 2022, as part of the 2023 annual operating and strategic plan process, the Company made the decision to transition microphone products to the Turtle Beach brand. As a result of this decision, there was no longer a basis for carrying the remaining net intangible assets related to the Neat brand. In the fourth quarter 2022, the Company recorded an impairment charge of $1.1 million related to the remaining Neat net intangible assets.

Amortization expense related to definite lived intangible assets of $0.0 million and $0.5 million was recognized for the three and six months ended June 30, 2023, respectively, and $0.3 million and $0.6 million was recognized for the three and six months ended June 30, 2022.

As of June 30, 2023, estimated annual amortization expense related to definite lived intangible assets in future periods was as follows:


	(in thousands)
2023	$	516
2024		1,003
2025		425
2026		170
Thereafter		-
Total	$	2,114

There were no changes in the carrying values of goodwill for the six months ended June 30, 2023 from the balance as of December 31, 2022.