The robust assessment of noise annoyance is of key importance given that it is the most prevalent community response in populations exposed to environmental noise. In 1993, the International Commission on Biological Effects of Noise Community Response to Noise team began formalizing a standardized methodology for assessing noise annoyance which resulted in reporting guidelines and recommendations later published as a Technical Specification (TS) in 2003 by the International Standards Organization (ISO) [(2003). ISO/TS 15666]. This TS, intended to inform the international community on the quantification of the exposure-response relationship between noise exposure and annoyance, has been in circulation for nearly two decades and was updated in 2021 by ISO [(2021). ISO/TS 15666] by an international working group (ISO TC43/SC1/WG62). This paper reviews use of the 2003 TS, identifies common adaptations in use, and summarizes the revisions. Methodological issues arising from the use of the 5-point verbal and the 11-point numeric scale questions and the scoring of "highly annoyed" are discussed. The revisions are designed to encourage further standardization in noise annoyance research. The paper highlights research needs that, if addressed, would strengthen the methodology underlying the assessment of noise annoyance including multidimensional assessments of annoyance.