1. (a) The Board recommends that the following standard symbols be used in recording hearing thresholds:

   1. (1) Right ear unmasked will be denoted as follows:

      1. (A) air ‑‑ a small circle;
      2. (B) bone ‑‑ a 45 degree angle pointing left.

   2. (2) Left ear unmasked will be denoted as follows:

      1. (A) air ‑‑ a small "x";
      2. (B) bone ‑‑ a 45 degree angle pointing right.

   3. (3) Right ear masked will be denoted as follows:

      1. (A) air ‑‑ a small triangle;
      2. (B) bone ‑‑ a single bracket open on the right.

   4. (4) Left ear masked will be denoted as follows:

      1. (A) air ‑‑ a small square;
      2. (B) bone ‑‑ a single bracket open on the left.
   5. (5) No response for the right ear at the maximum output of the audiometer will be denoted by a small arrow pointing southwest which is attached to the corresponding unmasked and masked symbols.
   6. (6) No response for the left ear at the maximum output of the audiometer will be denoted by a small arrow pointing southeast which is attached to the corresponding unmasked and masked symbols.
   7. (7) An asterisk will denote the contralateral ear masked.
   8. (8) A capital "S" will denote sound field responses.
2. (b) In all cases where the symbols listed in this Rule are not used, a symbol key shall be included on the audiogram form.

History Note: Authority G.S. 93D‑3(c);
Eff. April 23, 1976;
Amended Eff. May 1, 1988;
Pursuant to G.S. 150B-21.3A, rule is necessary without substantive public interest Eff. September 6, 2016.