A Hearing Screen and a Numbed Fingertip

A Checkup and a Cut

1Dawit Lemma is 13 and plays drums in his school’s jazz band. At band practice, the crash cymbals sit just to the right of his head, and he usually plays without earplugs. At his yearly checkup at Northgate Family Clinic, Dr. Ingrid Solano started with a hearing screen. The people and the clinic here are made up.

2Dawit sat in a quiet booth wearing headphones. A machine played short beeps of one pitch into one ear at a time, starting very soft and getting louder. Pitch is measured in hertz (Hz); a higher number means a higher pitch. Dawit pressed a button as soon as he heard each beep. The machine recorded the softest beep he heard, in decibels (dB). A smaller number means he could hear a softer sound. In this screen, 20 dB or less counts as typical hearing. Dr. Solano explained that deep inside each ear, sound-sensing hair cells detect vibrations and send signals along a nerve to the brain. Very loud sounds can damage hair cells, and the damage often shows up first at high pitches.

3Last week, Dawit cut the tip of his left index finger on a broken glass and came to the clinic for stitches. Before stitching, Dr. Solano injected numbing medicine near the base of the finger. The medicine stops the nerves in the finger from carrying signals for a few hours. To check it, nurse Bao Nguyen gently touched the fingertip 10 times with a thin, soft nylon thread while Dawit kept his eyes closed and said “yes” each time he felt a touch. She repeated the check several times. Once, at 15 minutes, Dawit opened his eyes and watched. “I can see it touching me,” he said, “but I can’t feel a thing.”

4At this week’s checkup, Nurse Nguyen carried in a tray with a needle for a flu shot. Before anyone came near him, Dawit’s heart began to pound and he tucked his left hand into his lap. His sister Selam, who is 3 and has never had stitches, watched the tray calmly.