The difference between Sounds and Dilators

THE DIFFERENCE BETWEEN SOUNDS AND DILATORS

By Chase-Simmons Industries


There is a lot of confusion about Sounds & Dilators. They are two entirely different animals for two entirely different purposes. Although Dilators may be used in some instances like sounds.


Let’s start with some definitions:

French Size: Most Sounds & Dilators (Hegars being a exception) are calibrated in French Sizes. French size is defined as millimeters in circumference or the distance around the shaft. Please do not confuse Diameter & Circumference! For practical purposes in this article, Circumference is approximately three times the diameter. For easy grasp of the concept of size, think of a Soda Straw (not a bar straw). 14fr will easily drop down a soda straw, a 16fr will still go inside, but an 18fr will not.

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Figure 1. Dittel and Van Buren Sounds

Dittel Sounds: are approximately 12 inches long and single ended. The insertion end is slightly tapered and straight (as opposed to being curved like the VanBuren Sound). The back end is wide and flat with the size stamped on it. They are available in 8fr to 40fr in even sizes. They are NOT sold in sets. (See Fig 1)

VanBuren Sounds: are approximately 12 inches long and single ended. The insertion end is slightly tapered with a 70 degree bend approximately 1 ½ inches behind the tip. The back end is wide and flat with the size stamped on it. They are available in 8fr to 40fr in even sizes. They are NOT sold in sets. (See Fig 1)

wpe8.jpg (2506 bytes)Hegar Uterine Dilators: are approximately 8 inches in length and double ended. One end being 1mm larger than the other. They have a general overall slender "S" shape. They are hollow steel, but closed ended (no fluid flow). They are sized in millimeters of diameter NOT French, and the size is stamped on the dilator. They are available singly or in sets of 8. The sizes are as follows: 3-4mm, 5-6mm, 7-8mm, 9-10mm, 11-12mm, 13-14mm, 15-16mm, 17-18mm. (See picture to the right - Set of Hegar Dilators)

wpe9.jpg (3043 bytes)Pratt Uterine Dilators: are approximately 10 ½ inches long and double ended. One end is one French size larger than the other and the size is stamped on the dilator. They are essentially straight except for a 15 degree bend about one inch back from each end. They are solid steel and heavier and longer than the Hegars. They are sized in French Sizes. They are available singly or in sets of 8. The sizes are as follows: 13-15fr, 17-19fr, 21-23fr, 25-27fr, 29-31fr, 33-35fr, 37-39fr 41-43fr. The actual diameter size range is approximately the is about the same as the Hegars. (See picture to the right - Set of Pratt Dilators)

There are other types of Sounds and Dilators with may different names (usually named after the doctor who designed them), but these are the most common ones encountered. Other systems of calibration are often encountered also. As many as three different calibrations may appear on some used sounds. There is almost always one for the French size.

Sounds (especially those described above) are for urethral insertion (sounding the depths). Dilators (especially those described above) are for cervical & uterine dilation (abortions, D & C, and other female procedures).

Many advertisements (and on the Internet) speak of Sets of Sounds for sale.

Usually these are Hegar Dilators. (Ask if they come in a little leatherette case. Ask if they are double ended. Ask about the shape.)

We have no objection to the use of dilators. We only want you to know what you are really buying! And their original intended use!

Sounds are more expensive that Dilators. If the price of the sound looks to low, you are probably getting dilators.

All Sounds & Dilators MUST be Sterile when inserted! This cannot be emphasized enough! A bladder or other transmitted disease is not fun! And can be tragic!

It is not the purpose of this article to cover sterilization or insertion. The MAIN purpose of this article is to make sure you know just what you are buying!

The Figures below are better explained in our C101 Document.

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A. Penile urethra being drawn over well-lubricated sound.

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B. Tip of sound in position for downward swing of sound.

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C. Completion of downward arc maneuver.

If you have questions, ASK!

The insertion of Sounds and Dilators in the male urethra CAN be a DANGEROUS procedure if NOT done PROPERLY! Again: If you have questions, ASK!