Does transmitted sound of killer whale scare whales?

Even with no sound, 40% of whales leave immediately.

When the sound was used, 15 out of 30 left immediately.

In this simulation, the null hypothesis is that the probability of a whale moving away is the no-sound probability:

Click Accumulate and simulate attempts to use the transmitted sound to get 30 whales to leave between 100 and 200 times. (Hold down the Simulate button.)

15 or more whales are scared off in about 15% of simulations, even if the device is ineffective so there is no evidence that the device is effective.

Emphasise the general concepts:

Null hypothesis, H0
Each whale has P(leaves) = 0.40
Alternative hypothesis, HA
P(leaves) > 0.40
Test statistic
Number of whales leaving
P-value
Probability of getting such a high test statistic if H0 is true
Conclusion
A small p-value gives evidence that H0 is not true.

Commercial fishermen occasionally have problems with whales scaring away fish. To see whether transmitting the sound of a killer whale gets the whales to leave, this was tried with 30 whales and 15 were immediately scared off. Even if no sound is transmitted, 40% of whales leave immediately. Is the device effective?