RT Book, Section A1 Shindler, Daniel M. A1 Shindler, Olga I. A1 Wright, Alicia SR Print(0) ID 1175624922 T1 Ultrasound T2 Practical Echocardiography for Cardiac Sonographers YR 2020 FD 2020 PB McGraw Hill PP New York, NY SN 9781260457797 LK accesscardiology.mhmedical.com/content.aspx?aid=1175624922 RD 2024/04/19 AB Sound frequencies above the audible range.Familiar example: A dog whistle.