ANSI‐1969 Standard Reference Threshold Sound‐Pressure Levels for Audiometers: Some Comments

New standard reference threshold sound‐pressure levels for four audiometric earphones are given in Appendix F of ANS “Specification for Audiometers” S3.6 (1969) effective 1 September 1970. The change in reference level from ASA (1951) to ANSI (1969) is shown to be different for each earphone type. The sources of data for these new reference levels and the relationship of these new levels to ISO standards is discussed.