This addendum provides changes to TSB-31-D@ Telecommunications ?C Telephone Terminal Equipment ?C Rationale and Measurement Guidelines for U.S. Network Protection. Clause 2 provides modifications to the text for the receive volume control test procedures and alternative test methods found in sub-clauses 14.2.5 and 14.2.6@ respectively@ of TSB-31-D. It also provides replacements for Figures 14.2-1 and 14.2-2. The other clauses and sub-clauses in TSB-31-D are not affected.