Is it possible to transfer data between cell phones using ultrasound with speakers and microphones?

No, because both speakers and microphones do not have such a wide bandwidth, the frequency of ultrasound is about 1MHz~30MHz (one million hertz~thirty million hertz)

And the best speakers have a bandwidth of at most 50kHz (50,000 hertz), and even better microphones can only recognize up to 30kHz (30,000 hertz), which is unrealistic. This is not realistic.