Subject: Changes in ANSI standards regarding 0 dB HL From: "Daniel E. Shub" <daniel.e.shub@xxxxxxxx> Date: Fri, 1 Apr 2016 11:27:18 -0400 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>I am feeling a bit over my head regarding the standard defining 0 dB HL. I have a set of longitudinal audiograms collected from 2000 through 2015 in the US. The audiograms are reported in dB HL and were measured according to the standard at the time and location of the measurement. >From what I can piece together, dB HL in the US is defined by ANSI S3.6 (written in 1969 and revised in 1989, 1996, 2004, and 2010). Has the relationship between dB HL and dB SPL (and maybe dB RETSPL) changed since the introduction of ANSI 3.6? If so, were clinics required to change to the newer standard on a particular date?