An evaluation of the CARL manikin for use in "patient-free" real ear measurement: consistency and comparison to normative data.

ABSTRACT

OBJECTIVE: Simulation-based learning experiences provide low-risk opportunities for procedural training and practice in audiology. A series of real ear measurements (REM) were completed using Clinical Assistant for Research and Learning (CARL) manikins to determine expected responses and to compare to normative data. DESIGN: (1) Real-ear Unaided Response (REUR) curves were measured with one CARL and each of three ear styles. (2) Test/retest reliability was evaluated by repeating each REUR. (3) Real ear to coupler difference (RECD) values for foam-tip and custom earmolds were calculated. (4) The reliability across copies of the CARL heads was evaluated by comparing REUR measurement from one set of ears on 4 heads. STUDY SAMPLE Four adult CARL manikins and thirty ears (5 sets of large, small, and bent). RESULTS: Within each ear category, the average difference across frequencies from one ear to the next was less than 2.5 dB with no significant individual difference more than 5.8 dB. Test/retest reliability was excellent. Typical REUR and RECD curves were created for each ear style and compared to published data on human ears. CONCLUSIONS: REM using the adult CARL head are predictable and repeatable making this simulator a good tool for audiological training.