Abstract: Poster Presentations |

Stethoscope Transmission Characteristics Using a Pure Tone Sweep versus Pink Noise Input FREE TO VIEW

Jonathan B. Waugh, PhD*; Dale C. Callahan, PhD; George A. Mathew, MS; Wesley M. Granger, PhD
Author and Funding Information

University of Alabama at Birmingham, Birmingham, AL


Chest. 2004;126(4_MeetingAbstracts):881S. doi:10.1378/chest.126.4_MeetingAbstracts.881S-a
Text Size: A A A
Published online


PURPOSE:  Many factors affect stethoscope sound transmission. Although bench measurements with an artificial pure tone make for a straightforward measurement, chest sounds have many different simultaneous frequencies. We compared stethoscope output using a 50-3000 Hz pure tone sweep and pink noise (50-10K Hz).

METHODS:  The sound transmission characteristics of a pure tone sweep and pink noise through a double-tubed diagnostic stethoscope were measured in an anechoic chamber using a computerized signal analysis system (CoolEdit and MATLAB®). The reference signal was measured at the chest piece and the earpiece (other earpiece occluded). A plot of frequency vs. decibel change is given below.

RESULTS:  The plot shows a difference between the shape of the pure tone sweep output and the pink noise output. The sweep output appears to develop periodic additive and subtractive nodes that would create signal distortion.

CONCLUSION:  Real use conditions would involve listening to multiple frequencies simultaneously. Using concurrent, multiple frequencies during bench testing appeared to limit confounding variables that are more likely to occur with pure tones.

CLINICAL IMPLICATIONS:  Clinicians using stethoscope comparisons for selection of a stethoscope should pay careful attention to the methodology employed and seek comparisons that use simultaneous multi-frequency analysis (natural or artificial).

DISCLOSURE:  J.B. Waugh, None.

Wednesday, October 27, 2004

12:30 PM- 2:00 PM




Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

CHEST Journal Articles
PubMed Articles
  • CHEST Journal
    Print ISSN: 0012-3692
    Online ISSN: 1931-3543