Which tympanometric type is indicated by a flat tracing across all probe tones?

Which tympanometric type is indicated by a flat tracing across all probe tones?

• A. Type A
• B. Type C
• C. Type Ad
• D. Type B

Answer: (D)

A flat tracing across all probe tones means the tympanic membrane isn’t moving at all in response to changes in air pressure. That absence of mobility produces no peak in the tympanogram, which is the hallmark of a Type B tympanogram. This pattern usually signals middle-ear pathology such as fluid-filled effusion or other problems preventing proper transmission of sound through the middle ear. Depending on ear-canal volume, a perforation or very large volume can also yield a flat trace, but the key idea is the lack of measurable compliance across the pressure range.

A flat tracing across all probe tones means the tympanic membrane isn’t moving at all in response to changes in air pressure. That absence of mobility produces no peak in the tympanogram, which is the hallmark of a Type B tympanogram. This pattern usually signals middle-ear pathology such as fluid-filled effusion or other problems preventing proper transmission of sound through the middle ear. Depending on ear-canal volume, a perforation or very large volume can also yield a flat trace, but the key idea is the lack of measurable compliance across the pressure range.