Click here for some great resources from Jane Madell, Ph.D. FAAA, CCC A/SLP, LSLS Cert AVT.
Her website includes resources for the LMH (Ling-Madell-Hewitt or "Low-Middle-High" frequency) test, which expands on the Ling Six test with 4 additional sounds for a total of 10 sounds. The test is provided for English and Spanish.
Test Yourself!