The positive: 1. Light, compact form factor, 2. Comfortable ear pieces, 3. Surprisingly good sound quality even without amplification, 4. 40X amplification and noise-canceling works well.Could be improved: 1. Instrument is absolutely unfriendly to hearing aids: earpiece does not occlude the ear canal when hearing aids are in place, so noise-canceling is ineffective and much of the benefit of the amplification is lost. •Provide an optional accessory: over-the-ear headphones (either a modern mechanical ear trumpet or electronically amplified) the earpieces could plug into for users with hearing aids. •Better yet, enable the Bluetooth to pair with and transmit real-time audio signal directly to a user’s hearing aids. That way, a user could keep the steth around their neck and still get great auscultation. It’s not rocket science, given that the Core already digitizes the audio signal and sends it via Bluetooth to the user’s cell phone. Having a patient’s heart & lung sounds audible in my hearing aids could be an enhanced feature I WOULD be willing to pay a monthly fee for. 2. The main purpose of the built-in Bluetooth communication with cell phone is to get us to subscribe—for a monthly fee—to a service most physicians don’t need. How many doctors need to send an audio file of heart sounds to anybody? By the same token, attaching the audio file of a patient’s heart/lung sounds to an EMR would provide legal evidence that the physician actually did examine the patient (or at least the chest). •Put the Bluetooth to good use for something physicians actually want: hearing heart sounds better. Enable the Core’s Bluetooth to pair with user’s hearing aids. Also, enable multiple channels of simultaneous Bluetooth receivers, so supervising physicians could have residents and medical students listen in for teaching purposes. Likewise, were universal Bluetooth pairing enabled, a Bluetooth speaker could be used for teaching in the (relatively quieter) classroom setting. I would pay a monthly fee for this capability. 3. The charging port is micro-USB, an inconvenient and obsolete connector, making the Core Steth out of step with everything else in my home and office. •Get with the times, Littmann. Change the charging port to USB-C. 4. The 40X amplification is good, but still inadequate. Evan at 40X, it’s difficult to hear subtleties of auscultation in a noisy ER or a busy private office. •Bump up the amplitude. 5. Battery life is just OK, but for those of us who are busy, we need at least a few days’ battery life. •We would be easily willing to tolerate a 40% increase in size and weight of the Core, to get a beefier battery (it’s so light and compact the way it is already) Bigger battery.Summary of suggestions for what would make Core perfect: •Enabled Bluetooth pairing with hearing aids/other Bluetooth receivers, •Over-the-ear headphones (mechanical or electronically amplified) the ear pieces could plug into, •More amplification, •Longer battery life, •USB-C charging portSummary:Littmann’s Core Digital Stethoscope is an elegant, giant leap forward in auscultation for clinicians. While I recommend it in it’s current incarnation, a reengineering could eliminate it’s shortcomings, making it the undisputed champion of clinical instruments, while enhancing it’s ROI for Littmann.